Design DB Structure for Scheduler

I am creating a scheduler of my own where user will be able to refresh their reports.

The high level test cases are : 1. Ability to run at specific time/day (e.g. 05/05/2015 3:15PM) 2. Ability to run multiple time a day(e.g. every 4 hrs from 12AM to 12PM) 3. Ability to schedule on specific day of week(e.g. every wed). 4. Ability to schedule at specific day each month (e.g. 1st of every month at 2.00 PM)

I have gone through this link : HERE

It satisfies my above 3 cases, however, I am a little skeptic on the 4th one