If you wanted even more flexible schedules, you might want to look into Later.js (http://bunkat.github.io/later/), a small library I created just for this purpose. It supports composite and exception schedules, cron schedules, and lots of different time periods. Everything can be specified using an API or using English text.
I also built replacements for setTimeout and setInterval to use Later schedules, so it should be easy enough to plug it into your solution.
I also built replacements for setTimeout and setInterval to use Later schedules, so it should be easy enough to plug it into your solution.