I have found that if you start saying yes too much, they will start taking advantage of you. I was in a situation last year where I had some medical issues and they helped me out a lot with rearranging my shifts so I could go to appointments, be in the hospital, etc. So at first I felt like I "owed" them return favors and every time they called me to come in or asked me to stay late, I basically said yes even though it was a complete inconvenience for me. Now things have settled in my personal life, I haven't so much as asked them for a favor in almost a year and I still get called all the time asking me to do things for them but basically not offering anything in return. Asking me to work Sunday night instead of Monday day during a week that I'm on days has nothing in it for me. If I do it, I don't even get a "thank you" or a "good morning" from the powers that be when they come in in the morning. So that, coupled with the fact that I'm now being treated poorly because I asked if my coworkers and I were going to get paid for the extra hour of the fall-back night (apparently you are supposed to just grin, bear it and feel lucky that you work for the hospital rather than asking if you are going to be paid for the hours that you worked) are making me not want to do them any favors ever again.