Originally Posted by LeineLodge

You can PD as many times as you want to throughout the year. You only get 1 APD per year. The APD only requires that there is 25% of the reserves required to be able to drop the trip, with limited exceptions for holiday periods. To see if you still have your APD available for the year, check your time card in iCrew. It will say something down near the bottom like APD available for use: Y (or N)

For a straight PD (again unlimited) every day of the trip has to have more reserves available than required. You can check this in iCrew under the Open Time link.

You cannot WS on a day which shows PD or APD on your schedule. I think you can PD just one day of the trip which will then drop the entire rotation, provided coverage is adequate. You would then have PD on only one day of your schedule, and should be able to WS on the other days. You want to check into this before you try it though - I'm not 100% on this one.

It sounds like you may be able to accomplish what you're wanting to do by a Swap With the Pot request, which has it's own set of requirements.