diff --git a/packages/@webex/plugin-meetings/src/meeting/index.ts b/packages/@webex/plugin-meetings/src/meeting/index.ts
index daf9ed31b96..650f5cb193e 100644
--- a/packages/@webex/plugin-meetings/src/meeting/index.ts
+++ b/packages/@webex/plugin-meetings/src/meeting/index.ts
@@ -538,6 +538,7 @@ export default class Meeting extends StatelessWebexPlugin {
   id: string;
   isMultistream: boolean;
   locusUrl: string;
+  #isoLocalClientMeetingJoinTime?: string;
   mediaConnections: any[];
   mediaId?: string;
   meetingFiniteStateMachine: any;
@@ -1521,6 +1522,17 @@ export default class Meeting extends StatelessWebexPlugin {
      * @memberof Meeting
      */
     this.iceCandidatesCount = 0;
+
+    /**
+     * Start time of meeting as an ISO string
+     * based on browser time, so can only be used to compute durations client side
+     * undefined if meeting has not been joined, set once on meeting join, and not updated again
+     * @instance
+     * @type {string}
+     * @private
+     * @memberof Meeting
+     */
+    this.#isoLocalClientMeetingJoinTime = undefined;
   }
 
   /**
@@ -1569,6 +1581,15 @@ export default class Meeting extends StatelessWebexPlugin {
     this.callStateForMetrics.correlationId = correlationId;
   }
 
+  /**
+   * Getter - Returns isoLocalClientMeetingJoinTime
+   * This will be set once on meeting join, and not updated again
+   * @returns {string | undefined}
+   */
+  get isoLocalClientMeetingJoinTime(): string | undefined {
+    return this.#isoLocalClientMeetingJoinTime;
+  }
+
   /**
    * Set meeting info and trigger `MEETING_INFO_AVAILABLE` event
    * @param {any} info
@@ -5235,6 +5256,8 @@ export default class Meeting extends StatelessWebexPlugin {
         // @ts-ignore
         this.webex.internal.device.meetingStarted();
 
+        this.#isoLocalClientMeetingJoinTime = new Date().toISOString();
+
         LoggerProxy.logger.log('Meeting:index#join --> Success');
 
         Metrics.sendBehavioralMetric(BEHAVIORAL_METRICS.JOIN_SUCCESS, {
diff --git a/packages/@webex/plugin-meetings/test/unit/spec/meeting/index.js b/packages/@webex/plugin-meetings/test/unit/spec/meeting/index.js
index 99bcb3a9cd9..2b947cfbdb6 100644
--- a/packages/@webex/plugin-meetings/test/unit/spec/meeting/index.js
+++ b/packages/@webex/plugin-meetings/test/unit/spec/meeting/index.js
@@ -331,6 +331,7 @@ describe('plugin-meetings', () => {
           assert.isNull(meeting.partner);
           assert.isNull(meeting.type);
           assert.isNull(meeting.owner);
+          assert.isUndefined(meeting.isoLocalClientMeetingJoinTime);
           assert.isNull(meeting.hostId);
           assert.isNull(meeting.policy);
           assert.instanceOf(meeting.meetingRequest, MeetingRequest);
@@ -1587,6 +1588,10 @@ describe('plugin-meetings', () => {
             sandbox.stub(MeetingUtil, 'joinMeeting').returns(Promise.resolve(joinMeetingResult));
           });
 
+          afterEach(() => {
+            assert.exists(meeting.isoLocalClientMeetingJoinTime);
+          });
+
           it('should join the meeting and return promise', async () => {
             const join = meeting.join({pstnAudioType: 'dial-in'});
             meeting.config.enableAutomaticLLM = true;