[Home](./index.md) > [@snowplow/react-native-tracker](./react-native-tracker.md) > [SessionState](./react-native-tracker.sessionstate.md) > [firstEventTimestamp](./react-native-tracker.sessionstate.firsteventtimestamp.md) ## SessionState.firstEventTimestamp property Optional date-time timestamp of when the first event in the session was tracked Signature: ```typescript firstEventTimestamp?: string; ```