It all depends on what is happening. For the P-3 guys, we were on a routine for the most part with day and night flights going off at the same time every day; but that was a few years ago. In the Gulf, could be around the clock, in Japan, not so much flight time unless there are submarine games to be played, then it could be around the clock. The ready in Misawa is the greatest deal ever; frosty pre-flight (winter), meet at the vans at noon, go to the commissary for luch and shopping then back for nap time, work out about 1500 then a nice home-cooked dinner or the O-club if your feeling spendy then movies in the suite.
At home I could get into the squadron about 0730-0800, sign whatever was in my inbox, look at some training jackets and then walk around with a blue folder so the CO, XO and Dept. Heads could see me. The blue folder is very important when trying to look busy and if anyone asks you who you are looking for, you will know who to say because you have already checked the flight sked and know who is out flying or on leave at the moment so he can't materialize right them and force your hand. You can be prepared for this, however, by having some sort of generic form with you or perhaps some PQS. Just be ready to once in while bite the bullet and actually do some work when not flying. As has already been said, if you are Legal, Trainig, OPS or readiness etc. you won't have to fake it, they'll get their work out of you.