Of course there are various nice widgets available for time entry, but if you want users to only set a date and change the time yourself, you can always do this in your 'Save' microflow. You can use addMinutes(addDays(trimToDays($value), 1),-1) for instance.
You can use a on change microflow on the datepicker, or change this in the save microflow.
If you also provide a different object for entering the end time you can do the following:
addMinutes(addHours(trimToDays($Object/EndDateTime), parseInteger(formatDateTime($Object/EndTime, 'HH'))),parseInteger(formatDateTime($Object/EndTime, 'mm')))
Hope this will help you.
Hnn, I would use the addMilliseconds instead of addMinutes if want to record the end of day. You otherwise might run into problems when comparing this date with other
If you want to allow a user to set different times you can use this widget to set the time portion of the date/time attribute