diff --git a/lib/utils/date-utils.js b/lib/utils/date-utils.js
index 221915040..a153a0f90 100644
--- a/lib/utils/date-utils.js
+++ b/lib/utils/date-utils.js
@@ -1,164 +1,164 @@
 // @flow
 
 import dateFormat from 'dateformat';
 import invariant from 'invariant';
 
 // Javascript uses 0-indexed months which is weird??
 function getDate(
   yearInput: number,
   monthInput: number,
   dayOfMonth: number,
 ): Date {
   return new Date(yearInput, monthInput - 1, dayOfMonth);
 }
 
 function padMonthOrDay(n: number): string | number {
   return n < 10 ? '0' + n : n;
 }
 
 function daysInMonth(year: number, month: number) {
   switch (month) {
     case 2:
       return (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0 ? 29 : 28;
     case 4:
     case 6:
     case 9:
     case 11:
       return 30;
     default:
       return 31;
   }
 }
 
 function dateString(
   first: Date | number,
   month?: number,
   day?: number,
 ): string {
   if (arguments.length === 1) {
     return dateFormat(first, 'yyyy-mm-dd');
   } else if (arguments.length === 3) {
     invariant(month && day, 'month/day should be set in call to dateString');
     invariant(typeof first === 'number', 'first param should be a number');
     return `${first}-${padMonthOrDay(month)}-${padMonthOrDay(day)}`;
   }
   invariant(false, 'incorrect number of params passed to dateString');
 }
 
 function startDateForYearAndMonth(year: number, month: number): string {
   return dateString(year, month, 1);
 }
 
 function endDateForYearAndMonth(year: number, month: number): string {
   return dateString(year, month, daysInMonth(year, month));
 }
 
 function fifteenDaysEarlier(timeZone?: ?string): string {
   const earlier = currentDateInTimeZone(timeZone);
   earlier.setDate(earlier.getDate() - 15);
   return dateString(earlier);
 }
 
 function fifteenDaysLater(timeZone?: ?string): string {
   const later = currentDateInTimeZone(timeZone);
   later.setDate(later.getDate() + 15);
   return dateString(later);
 }
 
 function prettyDate(dayString: string): string {
   return dateFormat(dateFromString(dayString), 'dddd, mmmm dS, yyyy');
 }
 
 function dateFromString(dayString: string): Date {
   const matches = dayString.match(/^([0-9]+)-([0-1][0-9])-([0-3][0-9])$/);
   invariant(matches && matches.length === 4, `invalid dayString ${dayString}`);
   return getDate(
     parseInt(matches[1], 10),
     parseInt(matches[2], 10),
     parseInt(matches[3], 10),
   );
 }
 
 const millisecondsInDay = 24 * 60 * 60 * 1000;
 const millisecondsInWeek = millisecondsInDay * 7;
 const millisecondsInYear = millisecondsInDay * 365;
 
 // Takes a millisecond timestamp and displays the time in the local timezone
-function shortAbsoluteDate(timestamp: number, timeZone?: ?string): string {
+function shortAbsoluteDate(timestamp: number): string {
   const now = Date.now();
   const msSince = now - timestamp;
-  const date = changeTimeZone(new Date(timestamp), timeZone);
+  const date = new Date(timestamp);
   if (msSince < millisecondsInDay) {
     return dateFormat(date, 'h:MM TT');
   } else if (msSince < millisecondsInWeek) {
     return dateFormat(date, 'ddd');
   } else if (msSince < millisecondsInYear) {
     return dateFormat(date, 'mmm d');
   } else {
     return dateFormat(date, 'mmm d yyyy');
   }
 }
 
 // Same as above, but longer
-function longAbsoluteDate(timestamp: number, timeZone?: ?string): string {
+function longAbsoluteDate(timestamp: number): string {
   const now = Date.now();
   const msSince = now - timestamp;
-  const date = changeTimeZone(new Date(timestamp), timeZone);
+  const date = new Date(timestamp);
   if (msSince < millisecondsInDay) {
     return dateFormat(date, 'h:MM TT');
   } else if (msSince < millisecondsInWeek) {
     return dateFormat(date, 'ddd h:MM TT');
   } else if (msSince < millisecondsInYear) {
     return dateFormat(date, 'mmmm d, h:MM TT');
   } else {
     return dateFormat(date, 'mmmm d yyyy, h:MM TT');
   }
 }
 
 function thisMonthDates(
   timeZone?: ?string,
 ): { startDate: string, endDate: string } {
   const now = currentDateInTimeZone(timeZone);
   const year = now.getFullYear();
   const month = now.getMonth() + 1;
   return {
     startDate: startDateForYearAndMonth(year, month),
     endDate: endDateForYearAndMonth(year, month),
   };
 }
 
 // The Date object doesn't support time zones, and is hardcoded to the server's
 // time zone. Thus, the best way to convert Date between time zones is to offset
 // the Date by the difference between the time zones
 function changeTimeZone(date: Date, timeZone: ?string): Date {
   if (!timeZone) {
     return date;
   }
   const localeString = date.toLocaleString('en-US', { timeZone });
   const localeDate = new Date(localeString);
   const diff = localeDate.getTime() - date.getTime();
   return new Date(date.getTime() + diff);
 }
 
 function currentDateInTimeZone(timeZone: ?string): Date {
   return changeTimeZone(new Date(), timeZone);
 }
 
 const threeDays = millisecondsInDay * 3;
 
 export {
   getDate,
   padMonthOrDay,
   dateString,
   startDateForYearAndMonth,
   endDateForYearAndMonth,
   fifteenDaysEarlier,
   fifteenDaysLater,
   prettyDate,
   dateFromString,
   shortAbsoluteDate,
   longAbsoluteDate,
   thisMonthDates,
   currentDateInTimeZone,
   threeDays,
 };
diff --git a/web/calendar/day.react.js b/web/calendar/day.react.js
index ccfed31d1..6fed498fd 100644
--- a/web/calendar/day.react.js
+++ b/web/calendar/day.react.js
@@ -1,265 +1,258 @@
 // @flow
 
 import classNames from 'classnames';
 import invariant from 'invariant';
 import _some from 'lodash/fp/some';
 import * as React from 'react';
 import { useDispatch } from 'react-redux';
 
 import {
   createLocalEntry,
   createLocalEntryActionType,
 } from 'lib/actions/entry-actions';
 import {
   useModalContext,
   type PushModal,
 } from 'lib/components/modal-provider.react';
 import { onScreenThreadInfos as onScreenThreadInfosSelector } from 'lib/selectors/thread-selectors';
 import { entryKey } from 'lib/shared/entry-utils';
 import type { EntryInfo } from 'lib/types/entry-types';
 import type { Dispatch } from 'lib/types/redux-types';
 import type { ThreadInfo } from 'lib/types/thread-types';
-import {
-  dateString,
-  dateFromString,
-  currentDateInTimeZone,
-} from 'lib/utils/date-utils';
+import { dateString, dateFromString } from 'lib/utils/date-utils';
 
 import LogInFirstModal from '../modals/account/log-in-first-modal.react';
 import HistoryModal from '../modals/history/history-modal.react';
 import ThreadPickerModal from '../modals/threads/thread-picker-modal.react';
 import { useSelector } from '../redux/redux-utils';
 import { htmlTargetFromEvent } from '../vector-utils';
 import { AddVector, HistoryVector } from '../vectors.react';
 import css from './calendar.css';
 import type { InnerEntry } from './entry.react';
 import Entry from './entry.react';
 
 type BaseProps = {
   +dayString: string,
   +entryInfos: $ReadOnlyArray<EntryInfo>,
   +startingTabIndex: number,
 };
 type Props = {
   ...BaseProps,
   +onScreenThreadInfos: $ReadOnlyArray<ThreadInfo>,
   +viewerID: ?string,
   +loggedIn: boolean,
   +nextLocalID: number,
-  +timeZone: ?string,
   +dispatch: Dispatch,
   +pushModal: PushModal,
   +popModal: () => void,
 };
 type State = {
   +hovered: boolean,
 };
 class Day extends React.PureComponent<Props, State> {
   state: State = {
     hovered: false,
   };
   entryContainer: ?HTMLDivElement;
   entryContainerSpacer: ?HTMLDivElement;
   actionLinks: ?HTMLDivElement;
   entries: Map<string, InnerEntry> = new Map();
 
   componentDidUpdate(prevProps: Props) {
     if (this.props.entryInfos.length > prevProps.entryInfos.length) {
       invariant(this.entryContainer, 'entryContainer ref not set');
       this.entryContainer.scrollTop = this.entryContainer.scrollHeight;
     }
   }
 
   render() {
-    const now = currentDateInTimeZone(this.props.timeZone);
+    const now = new Date();
     const isToday = dateString(now) === this.props.dayString;
     const tdClasses = classNames(css.day, { [css.currentDay]: isToday });
 
     let actionLinks = null;
     const hovered = this.state.hovered;
     if (hovered) {
       const actionLinksClassName = `${css.actionLinks} ${css.dayActionLinks}`;
       actionLinks = (
         <div className={actionLinksClassName} ref={this.actionLinksRef}>
           <a href="#" onClick={this.onAddEntry}>
             <AddVector />
             <span className={css.actionLinksText}>Add</span>
           </a>
           <a href="#" onClick={this.onHistory}>
             <HistoryVector className={css.history} />
             <span className={css.actionLinksText}>History</span>
           </a>
         </div>
       );
     }
 
     const entries = this.props.entryInfos
       .filter(entryInfo =>
         _some(['id', entryInfo.threadID])(this.props.onScreenThreadInfos),
       )
       .map((entryInfo, i) => {
         const key = entryKey(entryInfo);
         return (
           <Entry
             entryInfo={entryInfo}
             focusOnFirstEntryNewerThan={this.focusOnFirstEntryNewerThan}
             tabIndex={this.props.startingTabIndex + i}
             key={key}
             innerRef={this.entryRef}
           />
         );
       });
 
     const entryContainerClasses = classNames(css.entryContainer, {
       [css.focusedEntryContainer]: hovered,
     });
     const date = dateFromString(this.props.dayString);
     return (
       <td
         className={tdClasses}
         onClick={this.onClick}
         onMouseEnter={this.onMouseEnter}
         onMouseLeave={this.onMouseLeave}
       >
         <h2>{date.getDate()}</h2>
         <div className={entryContainerClasses} ref={this.entryContainerRef}>
           {entries}
           <div
             className={css.entryContainerSpacer}
             ref={this.entryContainerSpacerRef}
           />
         </div>
         {actionLinks}
       </td>
     );
   }
 
   actionLinksRef = (actionLinks: ?HTMLDivElement) => {
     this.actionLinks = actionLinks;
   };
 
   entryContainerRef = (entryContainer: ?HTMLDivElement) => {
     this.entryContainer = entryContainer;
   };
 
   entryContainerSpacerRef = (entryContainerSpacer: ?HTMLDivElement) => {
     this.entryContainerSpacer = entryContainerSpacer;
   };
 
   entryRef = (key: string, entry: InnerEntry) => {
     this.entries.set(key, entry);
   };
 
   onMouseEnter = () => {
     this.setState({ hovered: true });
   };
 
   onMouseLeave = () => {
     this.setState({ hovered: false });
   };
 
   onClick = (event: SyntheticEvent<HTMLTableCellElement>) => {
     const target = htmlTargetFromEvent(event);
     invariant(
       this.entryContainer instanceof HTMLDivElement,
       "entryContainer isn't div",
     );
     invariant(
       this.entryContainerSpacer instanceof HTMLDivElement,
       "entryContainerSpacer isn't div",
     );
     if (
       target === this.entryContainer ||
       target === this.entryContainerSpacer ||
       (this.actionLinks && target === this.actionLinks)
     ) {
       this.onAddEntry(event);
     }
   };
 
   onAddEntry = (event: SyntheticEvent<*>) => {
     event.preventDefault();
     invariant(
       this.props.onScreenThreadInfos.length > 0,
       "onAddEntry shouldn't be clicked if no onScreenThreadInfos",
     );
     if (this.props.onScreenThreadInfos.length === 1) {
       this.createNewEntry(this.props.onScreenThreadInfos[0].id);
     } else if (this.props.onScreenThreadInfos.length > 1) {
       this.props.pushModal(
         <ThreadPickerModal
           name="Chats"
           onClose={this.props.popModal}
           createNewEntry={this.createNewEntry}
         />,
       );
     }
   };
 
   createNewEntry = (threadID: string) => {
     if (!this.props.loggedIn) {
       this.props.pushModal(<LogInFirstModal inOrderTo="edit this calendar" />);
       return;
     }
     const viewerID = this.props.viewerID;
     invariant(viewerID, 'should have viewerID in order to create thread');
     this.props.dispatch({
       type: createLocalEntryActionType,
       payload: createLocalEntry(
         threadID,
         this.props.nextLocalID,
         this.props.dayString,
         viewerID,
       ),
     });
   };
 
   onHistory = (event: SyntheticEvent<HTMLAnchorElement>) => {
     event.preventDefault();
     this.props.pushModal(
       <HistoryModal mode="day" dayString={this.props.dayString} />,
     );
   };
 
   focusOnFirstEntryNewerThan = (time: number) => {
     const entryInfo = this.props.entryInfos.find(
       candidate => candidate.creationTime > time,
     );
     if (entryInfo) {
       const entry = this.entries.get(entryKey(entryInfo));
       invariant(entry, 'entry for entryinfo should be defined');
       entry.focus();
     }
   };
 }
 
 const ConnectedDay: React.ComponentType<BaseProps> = React.memo<BaseProps>(
   function ConnectedDay(props) {
     const onScreenThreadInfos = useSelector(onScreenThreadInfosSelector);
     const viewerID = useSelector(state => state.currentUserInfo?.id);
     const loggedIn = useSelector(
       state =>
         !!(state.currentUserInfo && !state.currentUserInfo.anonymous && true),
     );
     const nextLocalID = useSelector(state => state.nextLocalID);
-    const timeZone = useSelector(state => state.timeZone);
     const dispatch = useDispatch();
     const { pushModal, popModal } = useModalContext();
 
     return (
       <Day
         {...props}
         onScreenThreadInfos={onScreenThreadInfos}
         viewerID={viewerID}
         loggedIn={loggedIn}
         nextLocalID={nextLocalID}
-        timeZone={timeZone}
         dispatch={dispatch}
         pushModal={pushModal}
         popModal={popModal}
       />
     );
   },
 );
 
 export default ConnectedDay;
diff --git a/web/chat/chat-message-list.react.js b/web/chat/chat-message-list.react.js
index e0dc62316..ba7d69660 100644
--- a/web/chat/chat-message-list.react.js
+++ b/web/chat/chat-message-list.react.js
@@ -1,355 +1,350 @@
 // @flow
 
 import classNames from 'classnames';
 import { detect as detectBrowser } from 'detect-browser';
 import invariant from 'invariant';
 import * as React from 'react';
 
 import {
   fetchMessagesBeforeCursorActionTypes,
   fetchMessagesBeforeCursor,
   fetchMostRecentMessagesActionTypes,
   fetchMostRecentMessages,
 } from 'lib/actions/message-actions';
 import { registerFetchKey } from 'lib/reducers/loading-reducer';
 import {
   type ChatMessageItem,
   useMessageListData,
 } from 'lib/selectors/chat-selectors';
 import { messageKey } from 'lib/shared/message-utils';
 import { threadIsPending } from 'lib/shared/thread-utils';
 import type { FetchMessageInfosPayload } from 'lib/types/message-types';
 import { type ThreadInfo, threadTypes } from 'lib/types/thread-types';
 import {
   type DispatchActionPromise,
   useServerCall,
   useDispatchActionPromise,
 } from 'lib/utils/action-utils';
 
 import { type InputState, InputStateContext } from '../input/input-state';
 import LoadingIndicator from '../loading-indicator.react';
 import { useTextMessageRulesFunc } from '../markdown/rules.react';
 import { useSelector } from '../redux/redux-utils';
 import css from './chat-message-list.css';
 import { MessageListContext } from './message-list-types';
 import Message from './message.react';
 import RelationshipPrompt from './relationship-prompt/relationship-prompt';
 import { useTooltipContext } from './tooltip-provider';
 
 type BaseProps = {
   +threadInfo: ThreadInfo,
 };
 
 type Props = {
   ...BaseProps,
   // Redux state
   +activeChatThreadID: ?string,
   +messageListData: ?$ReadOnlyArray<ChatMessageItem>,
   +startReached: boolean,
-  +timeZone: ?string,
   +supportsReverseFlex: boolean,
   // Redux dispatch functions
   +dispatchActionPromise: DispatchActionPromise,
   // async functions that hit server APIs
   +fetchMessagesBeforeCursor: (
     threadID: string,
     beforeMessageID: string,
   ) => Promise<FetchMessageInfosPayload>,
   +fetchMostRecentMessages: (
     threadID: string,
   ) => Promise<FetchMessageInfosPayload>,
   // withInputState
   +inputState: ?InputState,
   +clearTooltip: () => mixed,
 };
 type Snapshot = {
   +scrollTop: number,
   +scrollHeight: number,
 };
 class ChatMessageList extends React.PureComponent<Props> {
   container: ?HTMLDivElement;
   messageContainer: ?HTMLDivElement;
   loadingFromScroll = false;
 
   componentDidMount() {
     this.scrollToBottom();
   }
 
   getSnapshotBeforeUpdate(prevProps: Props) {
     if (
       ChatMessageList.hasNewMessage(this.props, prevProps) &&
       this.messageContainer
     ) {
       const { scrollTop, scrollHeight } = this.messageContainer;
       return { scrollTop, scrollHeight };
     }
     return null;
   }
 
   static hasNewMessage(props: Props, prevProps: Props) {
     const { messageListData } = props;
     if (!messageListData || messageListData.length === 0) {
       return false;
     }
     const prevMessageListData = prevProps.messageListData;
     if (!prevMessageListData || prevMessageListData.length === 0) {
       return true;
     }
     return (
       ChatMessageList.keyExtractor(prevMessageListData[0]) !==
       ChatMessageList.keyExtractor(messageListData[0])
     );
   }
 
   componentDidUpdate(prevProps: Props, prevState, snapshot: ?Snapshot) {
     const { messageListData } = this.props;
     const prevMessageListData = prevProps.messageListData;
 
     if (
       this.loadingFromScroll &&
       messageListData &&
       (!prevMessageListData ||
         messageListData.length > prevMessageListData.length ||
         this.props.startReached)
     ) {
       this.loadingFromScroll = false;
     }
 
     const { messageContainer } = this;
     if (messageContainer && prevMessageListData !== messageListData) {
       this.onScroll();
     }
 
     // We'll scroll to the bottom if the user was already scrolled to the bottom
     // before the new message, or if the new message was composed locally
     const hasNewMessage = ChatMessageList.hasNewMessage(this.props, prevProps);
     if (
       this.props.activeChatThreadID !== prevProps.activeChatThreadID ||
       (hasNewMessage &&
         messageListData &&
         messageListData[0].itemType === 'message' &&
         messageListData[0].messageInfo.localID) ||
       (hasNewMessage && snapshot && Math.abs(snapshot.scrollTop) <= 1)
     ) {
       this.scrollToBottom();
     } else if (hasNewMessage && messageContainer && snapshot) {
       const { scrollTop, scrollHeight } = messageContainer;
       if (
         scrollHeight > snapshot.scrollHeight &&
         scrollTop === snapshot.scrollTop
       ) {
         const newHeight = scrollHeight - snapshot.scrollHeight;
         const newScrollTop = Math.abs(scrollTop) + newHeight;
         if (this.props.supportsReverseFlex) {
           messageContainer.scrollTop = -1 * newScrollTop;
         } else {
           messageContainer.scrollTop = newScrollTop;
         }
       }
     }
   }
 
   scrollToBottom() {
     if (this.messageContainer) {
       this.messageContainer.scrollTop = 0;
     }
   }
 
   static keyExtractor(item: ChatMessageItem) {
     if (item.itemType === 'loader') {
       return 'loader';
     }
     return messageKey(item.messageInfo);
   }
 
   renderItem = item => {
     if (item.itemType === 'loader') {
       return (
         <div key="loader" className={css.loading}>
           <LoadingIndicator status="loading" size="large" color="white" />
         </div>
       );
     }
     const { threadInfo } = this.props;
     invariant(threadInfo, 'ThreadInfo should be set if messageListData is');
     return (
       <Message
         item={item}
         threadInfo={threadInfo}
-        timeZone={this.props.timeZone}
         key={ChatMessageList.keyExtractor(item)}
       />
     );
   };
 
   render() {
     const { messageListData, threadInfo, inputState } = this.props;
     if (!messageListData) {
       return <div className={css.container} />;
     }
     invariant(inputState, 'InputState should be set');
     const messages = messageListData.map(this.renderItem);
 
     let relationshipPrompt = null;
     if (threadInfo.type === threadTypes.PERSONAL) {
       relationshipPrompt = <RelationshipPrompt threadInfo={threadInfo} />;
     }
 
     const messageContainerStyle = classNames({
       [css.messageContainer]: true,
       [css.mirroredMessageContainer]: !this.props.supportsReverseFlex,
     });
     return (
       <div className={css.outerMessageContainer}>
         {relationshipPrompt}
         <div className={messageContainerStyle} ref={this.messageContainerRef}>
           {messages}
         </div>
       </div>
     );
   }
 
   messageContainerRef = (messageContainer: ?HTMLDivElement) => {
     this.messageContainer = messageContainer;
     // In case we already have all the most recent messages,
     // but they're not enough
     this.possiblyLoadMoreMessages();
     if (messageContainer) {
       messageContainer.addEventListener('scroll', this.onScroll);
     }
   };
 
   onScroll = () => {
     if (!this.messageContainer) {
       return;
     }
     this.props.clearTooltip();
     this.possiblyLoadMoreMessages();
   };
 
   possiblyLoadMoreMessages() {
     if (!this.messageContainer) {
       return;
     }
 
     const { scrollTop, scrollHeight, clientHeight } = this.messageContainer;
     if (
       this.props.startReached ||
       Math.abs(scrollTop) + clientHeight + 55 < scrollHeight
     ) {
       return;
     }
 
     if (this.loadingFromScroll) {
       return;
     }
     this.loadingFromScroll = true;
 
     const threadID = this.props.activeChatThreadID;
     invariant(threadID, 'should be set');
 
     const oldestMessageServerID = this.oldestMessageServerID();
     if (oldestMessageServerID) {
       this.props.dispatchActionPromise(
         fetchMessagesBeforeCursorActionTypes,
         this.props.fetchMessagesBeforeCursor(threadID, oldestMessageServerID),
       );
     } else {
       this.props.dispatchActionPromise(
         fetchMostRecentMessagesActionTypes,
         this.props.fetchMostRecentMessages(threadID),
       );
     }
   }
 
   oldestMessageServerID(): ?string {
     const data = this.props.messageListData;
     invariant(data, 'should be set');
     for (let i = data.length - 1; i >= 0; i--) {
       if (data[i].itemType === 'message' && data[i].messageInfo.id) {
         return data[i].messageInfo.id;
       }
     }
     return null;
   }
 }
 
 registerFetchKey(fetchMessagesBeforeCursorActionTypes);
 registerFetchKey(fetchMostRecentMessagesActionTypes);
 const ConnectedChatMessageList: React.ComponentType<BaseProps> = React.memo<BaseProps>(
   function ConnectedChatMessageList(props: BaseProps): React.Node {
     const { threadInfo } = props;
     const userAgent = useSelector(state => state.userAgent);
     const supportsReverseFlex = React.useMemo(() => {
       const browser = detectBrowser(userAgent);
       return (
         !browser ||
         browser.name !== 'firefox' ||
         parseInt(browser.version) >= 81
       );
     }, [userAgent]);
 
-    const timeZone = useSelector(state => state.timeZone);
-
     const messageListData = useMessageListData({
       threadInfo,
       searching: false,
       userInfoInputArray: [],
     });
 
     const startReached = !!useSelector(state => {
       const activeID = threadInfo.id;
       if (!activeID) {
         return null;
       }
 
       if (threadIsPending(activeID)) {
         return true;
       }
 
       const threadMessageInfo = state.messageStore.threads[activeID];
       if (!threadMessageInfo) {
         return null;
       }
       return threadMessageInfo.startReached;
     });
 
     const dispatchActionPromise = useDispatchActionPromise();
     const callFetchMessagesBeforeCursor = useServerCall(
       fetchMessagesBeforeCursor,
     );
     const callFetchMostRecentMessages = useServerCall(fetchMostRecentMessages);
 
     const inputState = React.useContext(InputStateContext);
 
     const { clearTooltip } = useTooltipContext();
 
     const getTextMessageMarkdownRules = useTextMessageRulesFunc(threadInfo.id);
     const messageListContext = React.useMemo(() => {
       if (!getTextMessageMarkdownRules) {
         return undefined;
       }
       return { getTextMessageMarkdownRules };
     }, [getTextMessageMarkdownRules]);
 
     return (
       <MessageListContext.Provider value={messageListContext}>
         <ChatMessageList
           activeChatThreadID={threadInfo.id}
           threadInfo={threadInfo}
           messageListData={messageListData}
           startReached={startReached}
-          timeZone={timeZone}
           supportsReverseFlex={supportsReverseFlex}
           inputState={inputState}
           dispatchActionPromise={dispatchActionPromise}
           fetchMessagesBeforeCursor={callFetchMessagesBeforeCursor}
           fetchMostRecentMessages={callFetchMostRecentMessages}
           clearTooltip={clearTooltip}
         />
       </MessageListContext.Provider>
     );
   },
 );
 
 export default ConnectedChatMessageList;
diff --git a/web/chat/chat-thread-list-item.react.js b/web/chat/chat-thread-list-item.react.js
index 4cea476aa..5f090c064 100644
--- a/web/chat/chat-thread-list-item.react.js
+++ b/web/chat/chat-thread-list-item.react.js
@@ -1,163 +1,159 @@
 // @flow
 
 import classNames from 'classnames';
 import * as React from 'react';
 
 import type { ChatThreadItem } from 'lib/selectors/chat-selectors';
 import { useAncestorThreads } from 'lib/shared/ancestor-threads';
 import { shortAbsoluteDate } from 'lib/utils/date-utils';
 
 import { useSelector } from '../redux/redux-utils';
 import {
   useOnClickThread,
   useThreadIsActive,
 } from '../selectors/thread-selectors';
 import SWMansionIcon from '../SWMansionIcon.react';
 import ChatThreadListItemMenu from './chat-thread-list-item-menu.react';
 import ChatThreadListSeeMoreSidebars from './chat-thread-list-see-more-sidebars.react';
 import ChatThreadListSidebar from './chat-thread-list-sidebar.react';
 import css from './chat-thread-list.css';
 import MessagePreview from './message-preview.react';
 
 type Props = {
   +item: ChatThreadItem,
 };
 function ChatThreadListItem(props: Props): React.Node {
   const { item } = props;
   const {
     threadInfo,
     lastUpdatedTimeIncludingSidebars,
     mostRecentNonLocalMessage,
     mostRecentMessageInfo,
   } = item;
   const { id: threadID, currentUser } = threadInfo;
 
   const ancestorThreads = useAncestorThreads(threadInfo);
 
-  const timeZone = useSelector(state => state.timeZone);
-  const lastActivity = shortAbsoluteDate(
-    lastUpdatedTimeIncludingSidebars,
-    timeZone,
-  );
+  const lastActivity = shortAbsoluteDate(lastUpdatedTimeIncludingSidebars);
 
   const active = useThreadIsActive(threadID);
   const isCreateMode = useSelector(
     state => state.navInfo.chatMode === 'create',
   );
 
   const onClick = useOnClickThread(item.threadInfo);
 
   const selectItemIfNotActiveCreation = React.useCallback(
     (event: SyntheticEvent<HTMLAnchorElement>) => {
       if (!isCreateMode || !active) {
         onClick(event);
       }
     },
     [isCreateMode, active, onClick],
   );
 
   const containerClassName = classNames({
     [css.thread]: true,
     [css.activeThread]: active,
   });
 
   const { unread } = currentUser;
   const titleClassName = classNames({
     [css.title]: true,
     [css.unread]: unread,
   });
   const lastActivityClassName = classNames({
     [css.lastActivity]: true,
     [css.unread]: unread,
     [css.dark]: !unread,
   });
 
   const breadCrumbsClassName = classNames(css.breadCrumbs, {
     [css.unread]: unread,
   });
 
   let unreadDot;
   if (unread) {
     unreadDot = <div className={css.unreadDot} />;
   }
 
   const { color } = item.threadInfo;
   const colorSplotchStyle = React.useMemo(
     () => ({ backgroundColor: `#${color}` }),
     [color],
   );
 
   const sidebars = item.sidebars.map((sidebarItem, index) => {
     if (sidebarItem.type === 'sidebar') {
       const { type, ...sidebarInfo } = sidebarItem;
       return (
         <ChatThreadListSidebar
           sidebarInfo={sidebarInfo}
           isSubsequentItem={index > 0}
           key={sidebarInfo.threadInfo.id}
         />
       );
     } else if (sidebarItem.type === 'seeMore') {
       return (
         <ChatThreadListSeeMoreSidebars
           threadInfo={item.threadInfo}
           unread={sidebarItem.unread}
           key="seeMore"
         />
       );
     } else {
       return <div className={css.spacer} key="spacer" />;
     }
   });
 
   const ancestorPath = ancestorThreads.map((thread, idx) => {
     const isNotLast = idx !== ancestorThreads.length - 1;
     const chevron = isNotLast && (
       <span className={css.breadCrumb}>
         <SWMansionIcon icon="chevron-right" size={10} />
       </span>
     );
 
     return (
       <React.Fragment key={thread.id}>
         <span className={css.breadCrumb}>{thread.uiName}</span>
         {chevron}
       </React.Fragment>
     );
   });
 
   return (
     <>
       <a className={containerClassName} onClick={selectItemIfNotActiveCreation}>
         <div className={css.colorContainer}>
           <div className={css.colorSplotchContainer}>
             <div className={css.dotContainer}>{unreadDot}</div>
             <div className={css.colorSplotch} style={colorSplotchStyle} />
           </div>
         </div>
         <div className={css.threadButton}>
           <p className={breadCrumbsClassName}>{ancestorPath}</p>
           <div className={css.threadRow}>
             <div className={titleClassName}>{threadInfo.uiName}</div>
           </div>
           <div className={css.threadRow}>
             <MessagePreview
               messageInfo={mostRecentMessageInfo}
               threadInfo={threadInfo}
             />
           </div>
         </div>
         <div>
           <ChatThreadListItemMenu
             threadInfo={threadInfo}
             mostRecentNonLocalMessage={mostRecentNonLocalMessage}
           />
           <div className={lastActivityClassName}>{lastActivity}</div>
         </div>
       </a>
       {sidebars}
     </>
   );
 }
 
 export default ChatThreadListItem;
diff --git a/web/chat/message.react.js b/web/chat/message.react.js
index f8b6d4f99..9aab62ed4 100644
--- a/web/chat/message.react.js
+++ b/web/chat/message.react.js
@@ -1,52 +1,51 @@
 // @flow
 
 import invariant from 'invariant';
 import * as React from 'react';
 
 import { type ChatMessageInfoItem } from 'lib/selectors/chat-selectors';
 import { messageTypes } from 'lib/types/message-types';
 import { type ThreadInfo } from 'lib/types/thread-types';
 import { longAbsoluteDate } from 'lib/utils/date-utils';
 
 import css from './chat-message-list.css';
 import MultimediaMessage from './multimedia-message.react';
 import RobotextMessage from './robotext-message.react';
 import TextMessage from './text-message.react';
 
 type Props = {
   +item: ChatMessageInfoItem,
   +threadInfo: ThreadInfo,
-  +timeZone: ?string,
 };
 function Message(props: Props): React.Node {
-  const { item, timeZone } = props;
+  const { item } = props;
 
   let conversationHeader = null;
   if (item.startsConversation) {
     conversationHeader = (
       <div className={css.conversationHeader}>
-        {longAbsoluteDate(item.messageInfo.time, timeZone)}
+        {longAbsoluteDate(item.messageInfo.time)}
       </div>
     );
   }
   let message;
   if (item.messageInfo.type === messageTypes.TEXT) {
     message = <TextMessage item={item} threadInfo={props.threadInfo} />;
   } else if (
     item.messageInfo.type === messageTypes.IMAGES ||
     item.messageInfo.type === messageTypes.MULTIMEDIA
   ) {
     message = <MultimediaMessage item={item} threadInfo={props.threadInfo} />;
   } else {
     invariant(item.robotext, "Flow can't handle our fancy types :(");
     message = <RobotextMessage item={item} threadInfo={props.threadInfo} />;
   }
   return (
     <div className={css.message}>
       {conversationHeader}
       {message}
     </div>
   );
 }
 
 export default Message;
diff --git a/web/modals/threads/sidebars/sidebar.react.js b/web/modals/threads/sidebars/sidebar.react.js
index adf5a221a..607730fe0 100644
--- a/web/modals/threads/sidebars/sidebar.react.js
+++ b/web/modals/threads/sidebars/sidebar.react.js
@@ -1,86 +1,83 @@
 // @flow
 import classNames from 'classnames';
 import * as React from 'react';
 
 import { useModalContext } from 'lib/components/modal-provider.react';
 import type { ChatThreadItem } from 'lib/selectors/chat-selectors';
 import { getMessagePreview } from 'lib/shared/message-utils';
 import { shortAbsoluteDate } from 'lib/utils/date-utils';
 
 import Button from '../../../components/button.react';
 import { getDefaultTextMessageRules } from '../../../markdown/rules.react';
-import { useSelector } from '../../../redux/redux-utils';
 import { useOnClickThread } from '../../../selectors/thread-selectors';
 import css from './sidebars-modal.css';
 
 type Props = {
   +sidebar: ChatThreadItem,
   +isLastItem?: boolean,
 };
 
 function Sidebar(props: Props): React.Node {
   const { sidebar, isLastItem } = props;
   const { threadInfo, lastUpdatedTime, mostRecentMessageInfo } = sidebar;
   const { unread } = threadInfo.currentUser;
 
-  const timeZone = useSelector(state => state.timeZone);
   const { popModal } = useModalContext();
 
   const navigateToThread = useOnClickThread(threadInfo);
 
   const onClickThread = React.useCallback(
     event => {
       popModal();
       navigateToThread(event);
     },
     [popModal, navigateToThread],
   );
 
   const sidebarInfoClassName = classNames({
     [css.sidebarInfo]: true,
     [css.unread]: unread,
   });
 
-  const lastActivity = React.useMemo(
-    () => shortAbsoluteDate(lastUpdatedTime, timeZone),
-    [lastUpdatedTime, timeZone],
-  );
+  const lastActivity = React.useMemo(() => shortAbsoluteDate(lastUpdatedTime), [
+    lastUpdatedTime,
+  ]);
 
   const lastMessage = React.useMemo(() => {
     if (!mostRecentMessageInfo) {
       return <div className={css.noMessage}>No messages</div>;
     }
     const { message, username } = getMessagePreview(
       mostRecentMessageInfo,
       threadInfo,
       getDefaultTextMessageRules().simpleMarkdownRules,
     );
     const previewText = username ? `${username}: ${message}` : message;
     return (
       <>
         <div className={css.longTextEllipsis}>{previewText}</div>
         <div className={css.lastActivity}>{lastActivity}</div>
       </>
     );
   }, [lastActivity, mostRecentMessageInfo, threadInfo]);
 
   return (
     <Button className={css.sidebarContainer} onClick={onClickThread}>
       <img
         className={css.sidebarArrow}
         src={
           isLastItem
             ? 'images/arrow_sidebar_last.svg'
             : 'images/arrow_sidebar.svg'
         }
         alt="sidebar arrow"
       />
       <div className={sidebarInfoClassName}>
         <div className={css.longTextEllipsis}>{threadInfo.uiName}</div>
         <div className={css.lastMessage}>{lastMessage}</div>
       </div>
     </Button>
   );
 }
 
 export default Sidebar;
diff --git a/web/modals/threads/subchannels/subchannel.react.js b/web/modals/threads/subchannels/subchannel.react.js
index b21af6870..2b99b9535 100644
--- a/web/modals/threads/subchannels/subchannel.react.js
+++ b/web/modals/threads/subchannels/subchannel.react.js
@@ -1,84 +1,82 @@
 // @flow
 
 import classNames from 'classnames';
 import * as React from 'react';
 
 import { useModalContext } from 'lib/components/modal-provider.react';
 import { type ChatThreadItem } from 'lib/selectors/chat-selectors';
 import { getMessagePreview } from 'lib/shared/message-utils';
 import { shortAbsoluteDate } from 'lib/utils/date-utils';
 
 import Button from '../../../components/button.react';
 import { getDefaultTextMessageRules } from '../../../markdown/rules.react';
-import { useSelector } from '../../../redux/redux-utils';
 import { useOnClickThread } from '../../../selectors/thread-selectors';
 import SWMansionIcon from '../../../SWMansionIcon.react';
 import css from './subchannels-modal.css';
 
 type Props = {
   +chatThreadItem: ChatThreadItem,
 };
 
 function Subchannel(props: Props): React.Node {
   const { chatThreadItem } = props;
   const {
     threadInfo,
     mostRecentMessageInfo,
     lastUpdatedTimeIncludingSidebars,
   } = chatThreadItem;
 
   const { unread } = threadInfo.currentUser;
 
   const subchannelTitleClassName = classNames({
     [css.subchannelInfo]: true,
     [css.unread]: unread,
   });
 
-  const timeZone = useSelector(state => state.timeZone);
   const { popModal } = useModalContext();
 
   const navigateToThread = useOnClickThread(threadInfo);
 
   const onClickThread = React.useCallback(
     event => {
       popModal();
       navigateToThread(event);
     },
     [popModal, navigateToThread],
   );
 
   const lastActivity = React.useMemo(
-    () => shortAbsoluteDate(lastUpdatedTimeIncludingSidebars, timeZone),
-    [lastUpdatedTimeIncludingSidebars, timeZone],
+    () => shortAbsoluteDate(lastUpdatedTimeIncludingSidebars),
+    [lastUpdatedTimeIncludingSidebars],
   );
 
   const lastMessage = React.useMemo(() => {
     if (!mostRecentMessageInfo) {
       return <div className={css.noMessage}>No messages</div>;
     }
     const { message, username } = getMessagePreview(
       mostRecentMessageInfo,
       threadInfo,
       getDefaultTextMessageRules().simpleMarkdownRules,
     );
     const previewText = username ? `${username}: ${message}` : message;
     return (
       <>
         <div className={css.longTextEllipsis}>{previewText}</div>
         <div className={css.lastActivity}>{lastActivity}</div>
       </>
     );
   }, [lastActivity, mostRecentMessageInfo, threadInfo]);
 
   return (
     <Button className={css.subchannelContainer} onClick={onClickThread}>
       <SWMansionIcon icon="message-square" size={22} />
       <div className={subchannelTitleClassName}>
         <div className={css.longTextEllipsis}>{threadInfo.uiName}</div>
         <div className={css.lastMessage}>{lastMessage}</div>
       </div>
     </Button>
   );
 }
 
 export default Subchannel;
diff --git a/web/redux/redux-setup.js b/web/redux/redux-setup.js
index 8baa30d41..7b9b6bc5c 100644
--- a/web/redux/redux-setup.js
+++ b/web/redux/redux-setup.js
@@ -1,251 +1,250 @@
 // @flow
 
 import invariant from 'invariant';
 import type { PersistState } from 'redux-persist/src/types';
 
 import {
   logOutActionTypes,
   deleteAccountActionTypes,
 } from 'lib/actions/user-actions';
 import baseReducer from 'lib/reducers/master-reducer';
 import { mostRecentlyReadThreadSelector } from 'lib/selectors/thread-selectors';
 import { isLoggedIn } from 'lib/selectors/user-selectors';
 import { invalidSessionDowngrade } from 'lib/shared/account-utils';
 import type { Shape } from 'lib/types/core';
 import type { DraftStore } from 'lib/types/draft-types';
 import type { EnabledApps } from 'lib/types/enabled-apps';
 import type { EntryStore } from 'lib/types/entry-types';
 import type { CalendarFilter } from 'lib/types/filter-types';
 import type { LifecycleState } from 'lib/types/lifecycle-state-types';
 import type { LoadingStatus } from 'lib/types/loading-types';
 import type { MessageStore } from 'lib/types/message-types';
 import type { UserPolicies } from 'lib/types/policy-types.js';
 import type { BaseAction } from 'lib/types/redux-types';
 import type { ReportStore } from 'lib/types/report-types';
 import type { ConnectionInfo } from 'lib/types/socket-types';
 import type { ThreadStore } from 'lib/types/thread-types';
 import type { CurrentUserInfo, UserStore } from 'lib/types/user-types';
 import { setNewSessionActionType } from 'lib/utils/action-utils';
 
 import { activeThreadSelector } from '../selectors/nav-selectors';
 import { type NavInfo } from '../types/nav-types';
 import {
   updateWindowActiveActionType,
   setDeviceIDActionType,
   updateNavInfoActionType,
   updateWindowDimensionsActionType,
 } from './action-types';
 import { reduceDeviceID } from './device-id-reducer';
 import reduceNavInfo from './nav-reducer';
 import { getVisibility } from './visibility';
 
 export type WindowDimensions = { width: number, height: number };
 export type AppState = {
   navInfo: NavInfo,
   deviceID: ?string,
   currentUserInfo: ?CurrentUserInfo,
   draftStore: DraftStore,
   sessionID: ?string,
   entryStore: EntryStore,
   threadStore: ThreadStore,
   userStore: UserStore,
   messageStore: MessageStore,
   updatesCurrentAsOf: number,
   loadingStatuses: { [key: string]: { [idx: number]: LoadingStatus } },
   calendarFilters: $ReadOnlyArray<CalendarFilter>,
   urlPrefix: string,
   windowDimensions: WindowDimensions,
   cookie?: void,
   deviceToken?: void,
   baseHref: string,
   connection: ConnectionInfo,
   watchedThreadIDs: $ReadOnlyArray<string>,
   lifecycleState: LifecycleState,
   enabledApps: EnabledApps,
   reportStore: ReportStore,
   nextLocalID: number,
-  timeZone: ?string,
   userAgent: ?string,
   dataLoaded: boolean,
   windowActive: boolean,
   userPolicies: UserPolicies,
   _persist: ?PersistState,
 };
 
 export type Action =
   | BaseAction
   | { type: 'UPDATE_NAV_INFO', payload: Shape<NavInfo> }
   | {
       type: 'UPDATE_WINDOW_DIMENSIONS',
       payload: WindowDimensions,
     }
   | {
       type: 'UPDATE_WINDOW_ACTIVE',
       payload: boolean,
     }
   | {
       type: 'SET_DEVICE_ID',
       payload: string,
     };
 
 export function reducer(oldState: AppState | void, action: Action): AppState {
   invariant(oldState, 'should be set');
   let state = oldState;
 
   if (action.type === updateWindowDimensionsActionType) {
     return validateState(oldState, {
       ...state,
       windowDimensions: action.payload,
     });
   } else if (action.type === updateWindowActiveActionType) {
     return validateState(oldState, {
       ...state,
       windowActive: action.payload,
     });
   } else if (action.type === setNewSessionActionType) {
     if (
       invalidSessionDowngrade(
         oldState,
         action.payload.sessionChange.currentUserInfo,
         action.payload.preRequestUserState,
       )
     ) {
       return oldState;
     }
     state = {
       ...state,
       sessionID: action.payload.sessionChange.sessionID,
     };
   } else if (
     (action.type === logOutActionTypes.success &&
       invalidSessionDowngrade(
         oldState,
         action.payload.currentUserInfo,
         action.payload.preRequestUserState,
       )) ||
     (action.type === deleteAccountActionTypes.success &&
       invalidSessionDowngrade(
         oldState,
         action.payload.currentUserInfo,
         action.payload.preRequestUserState,
       ))
   ) {
     return oldState;
   }
 
   if (
     action.type !== updateNavInfoActionType &&
     action.type !== setDeviceIDActionType
   ) {
     state = baseReducer(state, action).state;
   }
 
   state = {
     ...state,
     navInfo: reduceNavInfo(
       state.navInfo,
       action,
       state.threadStore.threadInfos,
     ),
     deviceID: reduceDeviceID(state.deviceID, action),
   };
 
   return validateState(oldState, state);
 }
 
 function validateState(oldState: AppState, state: AppState): AppState {
   if (
     (state.navInfo.activeChatThreadID &&
       !state.navInfo.pendingThread &&
       !state.threadStore.threadInfos[state.navInfo.activeChatThreadID]) ||
     (!state.navInfo.activeChatThreadID && isLoggedIn(state))
   ) {
     // Makes sure the active thread always exists
     state = {
       ...state,
       navInfo: {
         ...state.navInfo,
         activeChatThreadID: mostRecentlyReadThreadSelector(state),
       },
     };
   }
 
   const activeThread = activeThreadSelector(state);
   if (
     activeThread &&
     !state.navInfo.pendingThread &&
     state.threadStore.threadInfos[activeThread].currentUser.unread &&
     getVisibility().hidden()
   ) {
     console.warn(
       `thread ${activeThread} is active and unread, ` +
         'but visibilityjs reports the window is not visible',
     );
   }
   if (
     activeThread &&
     !state.navInfo.pendingThread &&
     state.threadStore.threadInfos[activeThread].currentUser.unread &&
     typeof document !== 'undefined' &&
     document &&
     'hasFocus' in document &&
     !document.hasFocus()
   ) {
     console.warn(
       `thread ${activeThread} is active and unread, ` +
         'but document.hasFocus() is false',
     );
   }
   if (
     activeThread &&
     !getVisibility().hidden() &&
     typeof document !== 'undefined' &&
     document &&
     'hasFocus' in document &&
     document.hasFocus() &&
     !state.navInfo.pendingThread &&
     state.threadStore.threadInfos[activeThread].currentUser.unread
   ) {
     // Makes sure a currently focused thread is never unread
     state = {
       ...state,
       threadStore: {
         ...state.threadStore,
         threadInfos: {
           ...state.threadStore.threadInfos,
           [activeThread]: {
             ...state.threadStore.threadInfos[activeThread],
             currentUser: {
               ...state.threadStore.threadInfos[activeThread].currentUser,
               unread: false,
             },
           },
         },
       },
     };
   }
 
   const oldActiveThread = activeThreadSelector(oldState);
   if (
     activeThread &&
     oldActiveThread !== activeThread &&
     state.messageStore.threads[activeThread]
   ) {
     // Update messageStore.threads[activeThread].lastNavigatedTo
     state = {
       ...state,
       messageStore: {
         ...state.messageStore,
         threads: {
           ...state.messageStore.threads,
           [activeThread]: {
             ...state.messageStore.threads[activeThread],
             lastNavigatedTo: Date.now(),
           },
         },
       },
     };
   }
 
   return state;
 }
diff --git a/web/utils/tooltip-utils.js b/web/utils/tooltip-utils.js
index f9d2ab3c7..2be9aecc9 100644
--- a/web/utils/tooltip-utils.js
+++ b/web/utils/tooltip-utils.js
@@ -1,538 +1,535 @@
 // @flow
 
 import invariant from 'invariant';
 import * as React from 'react';
 
 import type { ChatMessageInfoItem } from 'lib/selectors/chat-selectors';
 import { createMessageReply } from 'lib/shared/message-utils';
 import {
   threadHasPermission,
   useSidebarExistsOrCanBeCreated,
 } from 'lib/shared/thread-utils';
 import { isComposableMessageType } from 'lib/types/message-types';
 import type { ThreadInfo } from 'lib/types/thread-types';
 import { threadPermissions } from 'lib/types/thread-types';
 import { longAbsoluteDate } from 'lib/utils/date-utils';
 
 import {
   tooltipButtonStyle,
   tooltipLabelStyle,
   tooltipStyle,
 } from '../chat/chat-constants';
 import MessageTooltip from '../chat/message-tooltip.react';
 import type { PositionInfo } from '../chat/position-types';
 import { useTooltipContext } from '../chat/tooltip-provider';
 import CommIcon from '../CommIcon.react';
 import { InputStateContext } from '../input/input-state';
-import { useSelector } from '../redux/redux-utils';
 import {
   useOnClickPendingSidebar,
   useOnClickThread,
 } from '../selectors/thread-selectors';
 import { calculateMaxTextWidth } from '../utils/text-utils';
 
 export const tooltipPositions = Object.freeze({
   LEFT: 'left',
   RIGHT: 'right',
   LEFT_BOTTOM: 'left-bottom',
   RIGHT_BOTTOM: 'right-bottom',
   LEFT_TOP: 'left-top',
   RIGHT_TOP: 'right-top',
   TOP: 'top',
   BOTTOM: 'bottom',
 });
 
 type TooltipSize = {
   +height: number,
   +width: number,
 };
 
 export type TooltipPositionStyle = {
   +anchorPoint: {
     +x: number,
     +y: number,
   },
   +verticalPosition: 'top' | 'bottom',
   +horizontalPosition: 'left' | 'right',
   +alignment: 'left' | 'center' | 'right',
 };
 
 export type TooltipPosition = $Values<typeof tooltipPositions>;
 
 export type MessageTooltipAction = {
   +label: string,
   +onClick: (SyntheticEvent<HTMLDivElement>) => mixed,
   +actionButtonContent: React.Node,
 };
 
 const appTopBarHeight = 65;
 
 const font =
   '14px "Inter", -apple-system, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", ' +
   '"Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", ui-sans-serif';
 
 type FindTooltipPositionArgs = {
   +sourcePositionInfo: PositionInfo,
   +tooltipSize: TooltipSize,
   +availablePositions: $ReadOnlyArray<TooltipPosition>,
   +defaultPosition: TooltipPosition,
   +preventDisplayingBelowSource?: boolean,
 };
 
 function findTooltipPosition({
   sourcePositionInfo,
   tooltipSize,
   availablePositions,
   defaultPosition,
   preventDisplayingBelowSource,
 }: FindTooltipPositionArgs): TooltipPosition {
   if (!window) {
     return defaultPosition;
   }
   const appContainerPositionInfo: PositionInfo = {
     height: window.innerHeight - appTopBarHeight,
     width: window.innerWidth,
     top: appTopBarHeight,
     bottom: window.innerHeight,
     left: 0,
     right: window.innerWidth,
   };
 
   const pointingTo = sourcePositionInfo;
   const {
     top: containerTop,
     left: containerLeft,
     right: containerRight,
     bottom: containerBottom,
   } = appContainerPositionInfo;
 
   const tooltipWidth = tooltipSize.width;
   const tooltipHeight = tooltipSize.height;
 
   const canBeDisplayedOnLeft = containerLeft + tooltipWidth <= pointingTo.left;
   const canBeDisplayedOnRight =
     tooltipWidth + pointingTo.right <= containerRight;
 
   const willCoverSidebarOnTopSideways =
     preventDisplayingBelowSource &&
     pointingTo.top + tooltipHeight > pointingTo.bottom;
 
   const canBeDisplayedOnTopSideways =
     pointingTo.top >= containerTop &&
     pointingTo.top + tooltipHeight <= containerBottom &&
     !willCoverSidebarOnTopSideways;
 
   const canBeDisplayedOnBottomSideways =
     pointingTo.bottom <= containerBottom &&
     pointingTo.bottom - tooltipHeight >= containerTop;
 
   const verticalCenterOfPointingTo = pointingTo.top + pointingTo.height / 2;
   const horizontalCenterOfPointingTo = pointingTo.left + pointingTo.width / 2;
 
   const willCoverSidebarInTheMiddleSideways =
     preventDisplayingBelowSource &&
     verticalCenterOfPointingTo + tooltipHeight / 2 > pointingTo.bottom;
 
   const canBeDisplayedInTheMiddleSideways =
     verticalCenterOfPointingTo - tooltipHeight / 2 >= containerTop &&
     verticalCenterOfPointingTo + tooltipHeight / 2 <= containerBottom &&
     !willCoverSidebarInTheMiddleSideways;
 
   const canBeDisplayedOnTop =
     pointingTo.top - tooltipHeight >= containerTop &&
     horizontalCenterOfPointingTo - tooltipWidth / 2 >= containerLeft &&
     horizontalCenterOfPointingTo + tooltipWidth / 2 <= containerRight;
 
   const canBeDisplayedOnBottom =
     pointingTo.bottom + tooltipHeight <= containerBottom &&
     horizontalCenterOfPointingTo - tooltipWidth / 2 >= containerLeft &&
     horizontalCenterOfPointingTo + tooltipWidth / 2 <= containerRight &&
     !preventDisplayingBelowSource;
 
   for (const tooltipPosition of availablePositions) {
     if (
       tooltipPosition === tooltipPositions.RIGHT &&
       canBeDisplayedOnRight &&
       canBeDisplayedInTheMiddleSideways
     ) {
       return tooltipPosition;
     } else if (
       tooltipPosition === tooltipPositions.RIGHT_BOTTOM &&
       canBeDisplayedOnRight &&
       canBeDisplayedOnBottomSideways
     ) {
       return tooltipPosition;
     } else if (
       tooltipPosition === tooltipPositions.LEFT &&
       canBeDisplayedOnLeft &&
       canBeDisplayedInTheMiddleSideways
     ) {
       return tooltipPosition;
     } else if (
       tooltipPosition === tooltipPositions.LEFT_BOTTOM &&
       canBeDisplayedOnLeft &&
       canBeDisplayedOnBottomSideways
     ) {
       return tooltipPosition;
     } else if (
       tooltipPosition === tooltipPositions.LEFT_TOP &&
       canBeDisplayedOnLeft &&
       canBeDisplayedOnTopSideways
     ) {
       return tooltipPosition;
     } else if (
       tooltipPosition === tooltipPositions.RIGHT_TOP &&
       canBeDisplayedOnRight &&
       canBeDisplayedOnTopSideways
     ) {
       return tooltipPosition;
     } else if (
       tooltipPosition === tooltipPositions.TOP &&
       canBeDisplayedOnTop
     ) {
       return tooltipPosition;
     } else if (
       tooltipPosition === tooltipPositions.BOTTOM &&
       canBeDisplayedOnBottom
     ) {
       return tooltipPosition;
     }
   }
   return defaultPosition;
 }
 
 type GetMessageActionTooltipStyleParams = {
   +sourcePositionInfo: PositionInfo,
   +tooltipSize: TooltipSize,
   +tooltipPosition: TooltipPosition,
 };
 
 function getMessageActionTooltipStyle({
   sourcePositionInfo,
   tooltipSize,
   tooltipPosition,
 }: GetMessageActionTooltipStyleParams): TooltipPositionStyle {
   if (tooltipPosition === tooltipPositions.RIGHT_TOP) {
     return {
       anchorPoint: {
         x: sourcePositionInfo.right,
         y: sourcePositionInfo.top,
       },
       horizontalPosition: 'right',
       verticalPosition: 'bottom',
       alignment: 'left',
     };
   } else if (tooltipPosition === tooltipPositions.LEFT_TOP) {
     return {
       anchorPoint: {
         x: sourcePositionInfo.left,
         y: sourcePositionInfo.top,
       },
       horizontalPosition: 'left',
       verticalPosition: 'bottom',
       alignment: 'right',
     };
   } else if (tooltipPosition === tooltipPositions.RIGHT_BOTTOM) {
     return {
       anchorPoint: {
         x: sourcePositionInfo.right,
         y: sourcePositionInfo.bottom,
       },
       horizontalPosition: 'right',
       verticalPosition: 'top',
       alignment: 'left',
     };
   } else if (tooltipPosition === tooltipPositions.LEFT_BOTTOM) {
     return {
       anchorPoint: {
         x: sourcePositionInfo.left,
         y: sourcePositionInfo.bottom,
       },
       horizontalPosition: 'left',
       verticalPosition: 'top',
       alignment: 'right',
     };
   } else if (tooltipPosition === tooltipPositions.LEFT) {
     return {
       anchorPoint: {
         x: sourcePositionInfo.left,
         y:
           sourcePositionInfo.top +
           sourcePositionInfo.height / 2 -
           tooltipSize.height / 2,
       },
       horizontalPosition: 'left',
       verticalPosition: 'bottom',
       alignment: 'right',
     };
   } else if (tooltipPosition === tooltipPositions.RIGHT) {
     return {
       anchorPoint: {
         x: sourcePositionInfo.right,
         y:
           sourcePositionInfo.top +
           sourcePositionInfo.height / 2 -
           tooltipSize.height / 2,
       },
       horizontalPosition: 'right',
       verticalPosition: 'bottom',
       alignment: 'left',
     };
   } else if (tooltipPosition === tooltipPositions.TOP) {
     return {
       anchorPoint: {
         x:
           sourcePositionInfo.left +
           sourcePositionInfo.width / 2 -
           tooltipSize.width / 2,
         y: sourcePositionInfo.top,
       },
       horizontalPosition: 'right',
       verticalPosition: 'top',
       alignment: 'center',
     };
   } else if (tooltipPosition === tooltipPositions.BOTTOM) {
     return {
       anchorPoint: {
         x:
           sourcePositionInfo.left +
           sourcePositionInfo.width / 2 -
           tooltipSize.width / 2,
         y: sourcePositionInfo.bottom,
       },
       horizontalPosition: 'right',
       verticalPosition: 'bottom',
       alignment: 'center',
     };
   }
   invariant(false, `Unexpected tooltip position value: ${tooltipPosition}`);
 }
 
 type CalculateTooltipSizeArgs = {
   +tooltipLabels: $ReadOnlyArray<string>,
   +timestamp: string,
 };
 
 function calculateTooltipSize({
   tooltipLabels,
   timestamp,
 }: CalculateTooltipSizeArgs): {
   +width: number,
   +height: number,
 } {
   const textWidth =
     calculateMaxTextWidth([...tooltipLabels, timestamp], font) +
     2 * tooltipLabelStyle.padding;
   const buttonsWidth =
     tooltipLabels.length *
     (tooltipButtonStyle.width +
       tooltipButtonStyle.paddingLeft +
       tooltipButtonStyle.paddingRight);
   const width =
     Math.max(textWidth, buttonsWidth) +
     tooltipStyle.paddingLeft +
     tooltipStyle.paddingRight;
   const height =
     (tooltipLabelStyle.height + 2 * tooltipLabelStyle.padding) * 2 +
     tooltipStyle.rowGap * 2 +
     tooltipButtonStyle.height;
   return {
     width,
     height,
   };
 }
 
 function useMessageTooltipSidebarAction(
   item: ChatMessageInfoItem,
   threadInfo: ThreadInfo,
 ): ?MessageTooltipAction {
   const { threadCreatedFromMessage, messageInfo } = item;
   const sidebarExists = !!threadCreatedFromMessage;
   const sidebarExistsOrCanBeCreated = useSidebarExistsOrCanBeCreated(
     threadInfo,
     item,
   );
   const openThread = useOnClickThread(threadCreatedFromMessage);
   const openPendingSidebar = useOnClickPendingSidebar(messageInfo, threadInfo);
   return React.useMemo(() => {
     if (!sidebarExistsOrCanBeCreated) {
       return null;
     }
     const buttonContent = <CommIcon icon="sidebar-filled" size={16} />;
     const onClick = (event: SyntheticEvent<HTMLElement>) => {
       if (threadCreatedFromMessage) {
         openThread(event);
       } else {
         openPendingSidebar(event);
       }
     };
     return {
       actionButtonContent: buttonContent,
       onClick,
       label: sidebarExists ? 'Go to thread' : 'Create thread',
     };
   }, [
     openPendingSidebar,
     openThread,
     sidebarExists,
     sidebarExistsOrCanBeCreated,
     threadCreatedFromMessage,
   ]);
 }
 
 function useMessageTooltipReplyAction(
   item: ChatMessageInfoItem,
   threadInfo: ThreadInfo,
 ): ?MessageTooltipAction {
   const { messageInfo } = item;
   const inputState = React.useContext(InputStateContext);
   invariant(inputState, 'inputState is required');
   const { addReply } = inputState;
   return React.useMemo(() => {
     if (
       !isComposableMessageType(item.messageInfo.type) ||
       !threadHasPermission(threadInfo, threadPermissions.VOICED)
     ) {
       return null;
     }
     const buttonContent = <CommIcon icon="reply-filled" size={18} />;
     const onClick = () => {
       if (!messageInfo.text) {
         return;
       }
       addReply(createMessageReply(messageInfo.text));
     };
     return {
       actionButtonContent: buttonContent,
       onClick,
       label: 'Reply',
     };
   }, [addReply, item.messageInfo.type, messageInfo, threadInfo]);
 }
 
 function useMessageTooltipActions(
   item: ChatMessageInfoItem,
   threadInfo: ThreadInfo,
 ): $ReadOnlyArray<MessageTooltipAction> {
   const sidebarAction = useMessageTooltipSidebarAction(item, threadInfo);
   const replyAction = useMessageTooltipReplyAction(item, threadInfo);
   return React.useMemo(() => [replyAction, sidebarAction].filter(Boolean), [
     replyAction,
     sidebarAction,
   ]);
 }
 
 type UseMessageTooltipArgs = {
   +availablePositions: $ReadOnlyArray<TooltipPosition>,
   +item: ChatMessageInfoItem,
   +threadInfo: ThreadInfo,
 };
 
 type UseMessageTooltipResult = {
   onMouseEnter: (event: SyntheticEvent<HTMLElement>) => void,
   onMouseLeave: ?() => mixed,
 };
 
 function useMessageTooltip({
   availablePositions,
   item,
   threadInfo,
 }: UseMessageTooltipArgs): UseMessageTooltipResult {
   const [onMouseLeave, setOnMouseLeave] = React.useState<?() => mixed>(null);
 
   const { renderTooltip } = useTooltipContext();
   const tooltipActions = useMessageTooltipActions(item, threadInfo);
 
   const containsInlineSidebar = !!item.threadCreatedFromMessage;
 
-  const timeZone = useSelector(state => state.timeZone);
-
   const messageTimestamp = React.useMemo(() => {
     const time = item.messageInfo.time;
-    return longAbsoluteDate(time, timeZone);
-  }, [item.messageInfo.time, timeZone]);
+    return longAbsoluteDate(time);
+  }, [item.messageInfo.time]);
 
   const tooltipSize = React.useMemo(() => {
     if (typeof document === 'undefined') {
       return {
         width: 0,
         height: 0,
       };
     }
     const tooltipLabels = tooltipActions.map(action => action.label);
     return calculateTooltipSize({
       tooltipLabels,
       timestamp: messageTimestamp,
     });
   }, [messageTimestamp, tooltipActions]);
 
   const onMouseEnter = React.useCallback(
     (event: SyntheticEvent<HTMLElement>) => {
       if (!renderTooltip) {
         return;
       }
       const rect = event.currentTarget.getBoundingClientRect();
       const { top, bottom, left, right, height, width } = rect;
       const messagePosition = { top, bottom, left, right, height, width };
 
       const tooltipPosition = findTooltipPosition({
         sourcePositionInfo: messagePosition,
         tooltipSize,
         availablePositions,
         defaultPosition: availablePositions[0],
         preventDisplayingBelowSource: containsInlineSidebar,
       });
       if (!tooltipPosition) {
         return;
       }
 
       const tooltipPositionStyle = getMessageActionTooltipStyle({
         tooltipPosition,
         sourcePositionInfo: messagePosition,
         tooltipSize: tooltipSize,
       });
 
       const { alignment } = tooltipPositionStyle;
 
       const tooltip = (
         <MessageTooltip
           actions={tooltipActions}
           messageTimestamp={messageTimestamp}
           alignment={alignment}
         />
       );
 
       const renderTooltipResult = renderTooltip({
         newNode: tooltip,
         tooltipPositionStyle,
       });
       if (renderTooltipResult) {
         const { onMouseLeaveCallback: callback } = renderTooltipResult;
         setOnMouseLeave((() => callback: () => () => mixed));
       }
     },
     [
       availablePositions,
       containsInlineSidebar,
       messageTimestamp,
       renderTooltip,
       tooltipActions,
       tooltipSize,
     ],
   );
 
   return {
     onMouseEnter,
     onMouseLeave,
   };
 }
 
 export {
   findTooltipPosition,
   calculateTooltipSize,
   getMessageActionTooltipStyle,
   useMessageTooltipSidebarAction,
   useMessageTooltipReplyAction,
   useMessageTooltipActions,
   useMessageTooltip,
 };