[Plugin: ICS Calendar] Repeating events repeating too often

For some reason, events that are scheduled to repeat monthly or (more specifically to my need) on the First Monday of Each Month are being displayed as repeating weekly.

My event was created on April 7th with repeat set to 1st Monday. The calendar page shows the event on the 14th, 21st and 28th. (I am limiting to 3 repeats) My second event, which happens every 2nd Monday with the first instance on April 14th, is showing as happening on April 14, 21 and 28.

Do I need to create a custom $ICAL_EVENTS_REPEAT_INTERVALS value?

I tried setting the repeat to a straight “Monthly” to make sure it wasn’t the custom repeat that was causing the issue. Monthly repeat (with the event on the 7th of each month, for instance) were displayed every week.

I have tried posting events both from Apple’s iCal (my pref) and from a Google Calendar.