You are paid a reserve guarantee of 75 hours. You are given 12 days off during the month. The days are pre picked and you bid by seniority for them.
We have a four hour call in period the day before our reserve day starting at 7pm. If you are assinged a trip you confirm it on the phone. If you don't have a trip the recording tells you whether you are released (never) If you are on the long call out list (they don't call you until after 12pm the next day. Never happens either) or what number you are out of the ready reserves. (it is always wrong unless it tells you that you are number 1)
Then, you try to go to bed as soon as you can because you could be called at any time. If you are on reserve for a 6 day period they can call you 24 hours a day for that 6 day period and you need to be at the airport specified as soon as humanly possible. They scare the heck out of you and everyone tries to break land speed records to get there. At some point you just tell yourself you'll get there when you get there or you could wind up crashing your car or having a heart attack when you get stuck in rush hour traffic.
It is always nice to get that phone call in the middle of your sleep that says get to the airport now because an international flight has been delayed 6 hours, the regular crew has gone illegal, and the passengers have all been waiting. You jump out of bed, throw on your outfit, drive (or take a cab) to the airport and find the passengers jeering at you and screaming "thanks for showing up" as they heckle you when you try to navigate through the crowded boarding area with one eye open because you are still half asleep.
You get the guarantee of 75 hours whether you fly or not. The FA's always fly on reserve. The pilots are the only ones who do used to not fly on reserve because they had the ability to pass trips up to the next most junior pilot. I don't know if they still have that ability. I don't think so.