If your app interacts with humans or machines in other time zones, tracking in a different time zone can be necessary. Though often people don’t want to specify

If your app interacts with humans or machines in other time zones, tracking in a different time zone can be necessary. Though often people don’t want to specify time zones with their complexities but instead specify times at locations. But I agree, generally your service doesn’t need time zones. The exception is necessary though when time zones get ambiguous or change (e.g. daylight savings going away)