[Remind-Fans] Question about Remind and the last Monday before a certain date

[Geoff Ball]

I'm trying to implement all of the Canadian holidays into my Remind  
calendar, and have completed all of them except one: Victoria Day.   
The definition of the holiday is "the last Monday before or on May 24."

I have no trouble with handling first Mondays of the month or third  
Sundays of the month, but this one has me baffled.

Thanks,
Geoff