[UglyToad]

Having built recurring stuff in the past (date based with no time component, luckily for me) I think you gain a lot of usability gains for generating a row for each occurrence of the event.

Inevitably the user will come back and say "oh, I want it monthly except this specific instance" or if it's a time based event "this specific one should be half an hour later". You could just store the exceptions to the rule as their own data-structure but then you need to correlate the exception to the scheduler 'tick' and if they can edit the schedule, well, you're S.O.O.L either way but I think having concrete occurrences is potentially easier to recover from.