Before Mavericks, I would respond to Alerts (was Alarms) to repeat in 2 hours, 5 min., 1 day, 1 day before event starts, etc., and when, for example, an alert repeats after 2 hours, I can then change the next repeat to 5 minutes...
Snooze-ing every 15 min. doesn't work (and gets very annoying): is this the 3rd or 6th snooze?
I don't want to have to create a new event each time an alert occurs. How do I vary the repeat?