Do you have a burning desire to be reminded of an appointment 12 minutes before it happens? Or 27.5 hours? Just type it in the reminder field as you create the appointment. You’ll need to use words, not shortcuts, in the reminder and snooze fields.

You can enter your own times when snoozing items also. But if you need to snooze something using ‘before start’ you’ll need to enter the number of minutes (or hours) between now and the desired reminder time, you can’t make your own ‘remind before start’ times.