Thank you!! Just tested this, and it worked for conditional formating. I had been playing with :extract for a while, but didn’t understand putting the date and month back to back as you suggested.
However, it doesn’t appear to work this way in workflows. For example, if I try to set a recurring event, it asks for the date to begin it on. I can’t find a way of inputting the equivalent of 10/16 that it will “accept”, and I can’t seem to use :extract to make it work either.