Reserve has 3 shifts. RS1=4am to 4pm, RS3=Noon to midnight, and RS4 7pm to 7am. RS4 goes junior and only awarded to one maybe two guys a month, so forget it until you are really senior.

As for RS1 and RS3, be prepared to sit Ready Reserve every day at the airport for 8 hours if you are not flying. It gets pretty old very quick.