If I enter an all-day event in ThunderBird and sync to phone, all is good. If I change it on my phone, it shifts back a day when synchronizing.
This has become very frustrating and I've almost missed things without double-checking.
My timezones on the phone and on my PC are the same. Running Windows 7 Pro on the PC and Android 5.1.1 on the phone. Both are set to the same timezone.