@qlm - I tried to do that. Tried to request every Tuesday off and was denied for that. And the funny thing, other coworkers of mine would get Tuesday off.
I've even tried to request a singular day off months in advance, and it would get denied. After putting in for the time to attend my nephew's wedding four months in advance and getting that denied a week before it happened, I just called out. When I returned, they had a writeup waiting for me. In the 14 years I've worked here, I've called out maybe three times. I told them to rip it up right where I stood or I am out the door.