Hi,
While it makes sense to have 5/10/15 minutes default reminder for events planned for a particular hour, the same cannot be said about full day events - then the reminder is pre-set to 23:45 or similar. While it may sound as a feature request, when I get woken up right before midnight, I would tend to think is a bug 
How about a separate option for full day reminders? Like:
Hourly event default reminder: 15 minutes.
Daily event default reminder: 1.5 day