Clarification Needed on Alert Record and Excluding Access Restrictions

Real-time Public Transport
1

I’m using Public Transport - Realtime - Alerts - v2 api to get Today’s realtime train/metro alerts. My filtering logic relies on the activePeriod’s start and end timestamps to determine if an alert is current. However, I received the following record:
{‘id’: ‘73d6d76f-a385-5ced-946c-bb4a6d9b6eb3’, ‘alert’: {‘activePeriod’: [{‘start’: ‘1659311997’}], ‘informedEntity’: [{‘agencyId’: ‘SydneyTrains’, ‘routeId’: ‘NSN_2a’, ‘directionId’: 1}, {‘agencyId’: ‘SydneyTrains’, ‘routeId’: ‘NSN_2i’, ‘directionId’: 1}, {‘agencyId’: ‘SydneyTrains’, ‘routeId’: ‘NSN_2k’, ‘directionId’: 1}, {‘agencyId’: ‘SydneyTrains’, ‘routeId’: ‘NSN_1a’, ‘directionId’: 0}], ‘cause’: ‘UNKNOWN_CAUSE’, ‘effect’: ‘UNKNOWN_EFFECT’, ‘url’: {‘translation’: [{‘text’: ‘https://transportnsw.info/alerts#/train’, ‘language’: ‘en’}]}, ‘headerText’: {‘translation’: [{‘text’: 'North Shore Line ', ‘language’: ‘en’}]}, ‘descriptionText’: {‘translation’: [{‘text’: ‘Trains are running late due to urgent signal repairs at Milsons Point. Stops may change at short notice. Please allow extra travel time, listen for announcements and check transport apps or information screens before boarding trains.’, ‘language’: ‘en’}, {‘text’: ‘Trains are running late due to urgent signal repairs at Milsons Point. Stops may change at short notice. Please allow extra travel time, listen for announcements and check transport apps or information screens before boarding trains.’, ‘language’: ‘en/html’}]}}},

Since the start timestamp (1659311997) dates back to 2022, I believe this alert should be considered expired. However, because there is no end timestamp provided, I cannot accurately determine whether the alert is ongoing or has already expired. Could you please review this record and advise if this is a data issue or if there is an alternative method to determine the alert’s current status?

Additionally, I am looking to exclude alerts related to access restrictions from my results. Is there a built-in way to filter these out, or would I need to rely on keyword-based filtering?

Thank you for your assistance.
Yvonne