[Backup Service] Existing repositories not aware of timezone changes.

Description:

The next scheduled time is not updated when the timezone changes.

Steps to reproduce:

1. Start a hourly backup plan at 0745 on the 6th of November with the time set as UTC.
2. Take the next scheduled backup at 9am UTC time.
3. Change the timezone to Pacific/Apia.
4. At this point it's okay for the backup service to not be aware of the timezone change as the next scheduled time was calculated according to the UTC timezone.

So we can take the next scheduled backup in 1 hour as expected.

The task history currently looks like this after the backup:

1. At this point the backup service should become aware of the timezone change as it recalculates the next scheduled time for task0, however it still reports the next scheduled time in UTC.

Expected behaviour:

I expected the next time to account for the timezone change.

Side note:

I created another repository and it also calculates the next time in UTC.

This is super weird as the code calls time.Now() to calculate the next time which should account for the timezone.