Paok Im not a planner so dont hold me to it but I believe you would also have to be legal for the window as well an a6 cant be a lc 1 the next day cause of the rest requirement. So I would assume that they usually only get the early people who would be legal for it

a1-a3 would be the windows I believe that can do a window change unless previously notified. However I'm not up on that part of the contract cause it doesen't concern me, I'm day of operations.

Sorry but I would call Planning and they will go over it with you