Ruby Date Recurrence Library - Allows easy creation of recurrence rules and fast querying

ice_cube is a ruby library for easily handling repeated events (schedules). The API is modeled after iCalendar events, in a pleasant Ruby syntax. The power lies in the ability to specify multiple rules, and have ice_cube quickly figure out whether the schedule falls on a certain date (.occurs_on?), or what times it occurs at (.occurrences, .first, .all_occurrences).