It is very much frowned upon to ask for 2 days in a heavy month before the schedule comes out. My boss let me do it last time because (1) I was new and didn't know, and (2) because I was new, I didn't have as much that needed to be scheduled.
Next year, there is a good chance that the training I took last year will be on the Friday of Beltane. (My two co-workers that are in training are taking the training I did last year.) My job requires a certain number of certain types of training hours every 2 years, those hours are not always easy to come by, and this all-day training completes the hours. (Oh, and it's free.) If I don't take the training, I have to find my own training hours and pay for them.