When I create a new appointment and want to set a reminder the default value is 60 minutes before, which is fine.
Then you have the option to add another "custom" reminder which I usually use to add the alternative "1 Day before".

But the default suggestions are:
* at the time of the event
* 10 minutes
* 30 minutes
* 1 hour
* 1 week
* CUSTOM

which means that you always have to press custom and, edit the predefined value (which is 15),
set the value to 1 instead, and then finally choose the option "Days" and click Done.

I believe there is an unecessary big gap between the predefined 1 Hour to 1 week? The option to be reminded 1 day ahead is somewhat buried in several steps.

Just my opinion, maybe there are many more users that would have the 1 Day reminder more accessible?

Keep up the good work!