Ignore Muttley,
Book it, ring crewing and ask them to put a note on the system and then email the FDM and cc crewing and fleet super intendant, worked just fine for me last year. I did follow it up with a call to crewing 3 days before to remind them, but got the day before and the day itself xx. And no, that wasn't because I needed legal days off, I did only 2 trips my whole rsv month.