Can find dates that match certain criteria. Eg:

The next three tuesdays: DateFinderBase.weekly.day(:tuesday).find(:max => 3)

The last Monday for the next three months: DateFinderBase.monthly.day(:monday).day_occurrence(:last).find(:max => 3)

You can string as many conditions together as you like:

day(day) - A string (eg: friday), or an integer from 0 to 6 (0 = Sunday)
day_number(number) - An integer, the day of the month.
weekday - The day must be a weekday
day_occurrence(type) - One of first, second, third, fourth, last. The day must be the given occurence in the month.
month(month) - Like day, either a string or an integer from 1 to 12