all day events
Fix the bug where all-day events slide back to the preceding day for arbitrary reasons.
T Zam commented
Alas, this isn't a bug but a hugely problematic "feature" that doesn't actually pin all day events to the date, but to midnight-midnight in whatever time zone it's set to at the time. this means that when you are not in that time zone, your notifications and reminders end up starting or ending on the wrong day.
This is likely more a time zone issue or changing the time on the clock. The real issue is 'All-Day Events' should have no time associated with them. They are all-day events no matter what time zone.