Once you updated to iOS on your iPad or iPhone, you can experience Bluetooth issues when trying to set or edit a date or time of an event within Calendars 5. Thereby you are unable to choose the actual date, time, make it an all day event and etc.
The date and time picker does not appear because of the Bluetooth keyboard attached to your device. In order to cope with the issue, you can disable Bluetooth or use a button to call on-screen keyboard.
If you use Apple Wireless Keyboard, you can press the Eject button on your keyboard to call on-screen keyboard.
If you use Logitech Ultrathin Bluetooth Keyboard, to call on-screen keyboard you need to press FN+3
To call on-screen keyboard with Logitech Folio Bluetooth Keyboard, please press FN+5 or FN+6.
Once you have managed to call the on-screen keyboard, you get a possibility to adjust the date and time of the appointment.