Passenger's technology is built to automatically adjust around daylight savings time changes, so you don't need to do anything on your end. Here are the details about how Passenger adjusts to the clock change twice a year.
In the UK the clocks go forward 1 hour at 1am on the last Sunday in March (BST, which is UTC + 1 hour), and back 1 hour at 2am on the last Sunday in October (GMT, which is UTC + 0 hours). UTC refers to Coordinated Universal Time, which is a reference point to compare time zones.
We use the phrase "local time" to refer to the time that would normally be displayed on a watch or clock at that time.
Tickets expiring at a set time
For tickets that expire at a set time (eg at the end of an operating day), they will always expire at the set local time. Eg, with a 4am expiry, a day ticket:
- activated on 1st Jan would expire at 4am GMT on the 2nd Jan
- activated on 1st August would expire at 4am BST on the 2nd August
- activated on the last day of BST would expire at 4am on the first day of GMT
- activated on the last day of GMT would expire at 4am on the first day of BST
Tickets expiring after a set period
Tickets that expire after a set period are always valid for that whole period. This can be confusing when this period crosses a BST/GMT change as it looks like an hour has been lost or gained. As a rule, if you started a stopwatch then no matter what the time zone is, the ticket would expire after the correct number of hours.
For example, a 24-hour ticket:
- activated at midday on 1st Jan would expire 24 hours later, which is midday GMT on the 2nd Jan
- activated at midday on 1st August would expire 24 hours later, which is at midday BST on the 2nd August
- activated at midday on the last day of BST would expire 24 hours later, which is at 11am on the first day of GMT
- activated at midday on the last day of GMT would expire 24 hours later, which is at 1pm on the first day of BST
- This same logic would also apply to a week or 30 day ticket.
Passenger cloud always shows times in their local time. That means that "12:00 on 1st Jan" would always be GMT and "12:00 on 1st August" would always be BST. These times won't change, even if you look at them in a different time zone.
Times in CSV exports are in ISO 8601 format and always include a timezone, which should be interpreted by any software that reads them.
Apps always show times in their local time, the same as Passenger Cloud. If a user's device is set to a different time zone then the app warns them and, in some cases, disables the ticket.
Note: for tickets longer than a day, apps will show a countdown in days and hours. A 7 day (168 hour) ticket that's valid before and after the BST/GMT switch at the end of October will expire in 6 days and 23 hours. Although this looks wrong, this is actually correct, as one of the days is 25 hours long! For the avoidance of doubt, customers do not gain or lose an hour here. Starting a stopwatch when a ticket is activated will always show the correct number of hours when the ticket expires.