After a thorough search of the web for documentation of how recurence works in MCAL, or even for documentation of the recurence function parameters, I found nothing. So, I gave up and dove into the MCAL source code for answers, and this is what I have found. Please keep in mind that this is all "As far as I can tell" information.
First of all, I believe that mcal_list_events DOES return events that recur in the range being searched.
The mcal_event_set_recur_* functions take in an mcal stream, and date for the event to stop recuring by (given by day, month, year), and an "interval".
mcal_event_set_recur_weekly takes an additional integer parameter "weekdays" which is basicly a binary mask created by bitwise ANDing together integers representing the days of the week.
Sunday = 1
Monday = 2
Tuesday = 4
Wednesday = 8
Thursday = 16
Friday = 32
Saturday = 64
So if I wanted the value that represented "Monday, Wednesday, and Friday" I would do this:
$weekdays = 2 & 8 & 32;
Here is how to interpret "interval" and "weekdays".
This event should recur every "interval" days.
This event should recur on every day specified in "weekdays", and should do so every "interval" weeks.
This event should recur on the "interval" day of every month.
This event should recur every on every Xday of the Yth week of the month, every "interval" months. (Where Xday is a day of the week, e.g. Monday, Tuesday, etc. Note: This is the one I am the least sure about though it seems to be the logical assumption for how it should work based on the fact that there are two monthly functions and the other one's operation is intuitive.)
This event should recur every "interval" years.