diff --git a/web/chat/chat-thread-list-item.react.js b/web/chat/chat-thread-list-item.react.js
--- a/web/chat/chat-thread-list-item.react.js
+++ b/web/chat/chat-thread-list-item.react.js
@@ -23,15 +23,28 @@
   +item: ChatThreadItem,
   +setModal: (modal: ?React.Node) => void,
 };
+
+function useLastActiveTime(item: ChatThreadItem): string {
+  const timeZone = useSelector(state => state.timeZone);
+  const lastUpdatedTimes = item.sidebars.map(sidebar => {
+    if (sidebar.type === 'sidebar') {
+      return sidebar.lastUpdatedTime;
+    } else {
+      return 0;
+    }
+  });
+
+  const recentLastTime = Math.max(item.lastUpdatedTime, ...lastUpdatedTimes);
+  return shortAbsoluteDate(recentLastTime, timeZone);
+}
+
 function ChatThreadListItem(props: Props): React.Node {
   const { item, setModal } = props;
   const { threadInfo } = item;
   const threadID = item.threadInfo.id;
   const ancestorThreads = useAncestorThreads(threadInfo);
   const onClick = useOnClickThread(threadID);
-
-  const timeZone = useSelector(state => state.timeZone);
-  const lastActivity = shortAbsoluteDate(item.lastUpdatedTime, timeZone);
+  const lastActivity = useLastActiveTime(item);
 
   const active = useThreadIsActive(threadID);
   const containerClassName = React.useMemo(
diff --git a/web/chat/sidebar-item.react.js b/web/chat/sidebar-item.react.js
--- a/web/chat/sidebar-item.react.js
+++ b/web/chat/sidebar-item.react.js
@@ -4,9 +4,7 @@
 import * as React from 'react';
 
 import type { SidebarInfo } from 'lib/types/thread-types';
-import { shortAbsoluteDate } from 'lib/utils/date-utils';
 
-import { useSelector } from '../redux/redux-utils';
 import { useOnClickThread } from '../selectors/nav-selectors';
 import SWMansionIcon from '../SWMansionIcon.react';
 import css from './chat-thread-list.css';
@@ -15,16 +13,12 @@
   +sidebarInfo: SidebarInfo,
 };
 function SidebarItem(props: Props): React.Node {
-  const { threadInfo, lastUpdatedTime } = props.sidebarInfo;
+  const { threadInfo } = props.sidebarInfo;
   const threadID = threadInfo.id;
-
   const onClick = useOnClickThread(threadID);
-
-  const timeZone = useSelector(state => state.timeZone);
-  const lastActivity = shortAbsoluteDate(lastUpdatedTime, timeZone);
-
   const { unread } = threadInfo.currentUser;
   const unreadCls = classNames(css.sidebarTitle, { [css.unread]: unread });
+
   return (
     <>
       <SWMansionIcon icon="right-angle-arrow" size={28} />
@@ -32,14 +26,6 @@
       <a className={css.threadButtonSidebar} onClick={onClick}>
         <div className={css.threadRow}>
           <div className={unreadCls}>{threadInfo.uiName}</div>
-          <div
-            className={classNames([
-              css.sidebarLastActivity,
-              unread ? css.black : css.dark,
-            ])}
-          >
-            {lastActivity}
-          </div>
         </div>
       </a>
     </>