I think we are saying the same thing just differently. What’s in the posted schedule matters for spot leave. Up until the schedule is posted spot leave is not guaranteed. For example, if I had spot leave approved in the posted schedule for Monday and someone today made a military leave request for Monday, management can’t cancel my spot leave and reassign me to to the shift. They would have to approve the military leave and call in OT to cover the shift. If both a request for spot leave and military leave was made for the same day before the schedule posted, and even if the spot leave request was first, the military leave would be the one approved in the posted schedule. Sound like we’re saying the same thing or you have a different understanding?
to answer your question in the middle, yes the absolutely are allowed to cancel your spot leave approval for Monday. Most likely at all facilities it would not happen, but it is allowed.
You are confusing the prior to the posting and what spot leave is. During the bidding process the amount of days and what days throughout the year are collaboratively pre-determined. all those days or slots if bid prior to 30 days of the posting of the schedule (28 prior to the first day of the PP, 58 days at a minimum prior to the fist day of the pp) are guaranteed. So lets say on August 16th, there are 2 slots. during the bid process only one slot is taken, then in march someone requests the other, both days will be guaranteed and cannot be removed. however if both slots are taken during the bid process and you put in a request for that day it is considered spot leave. lets say management approves that day well in advance, lets say 45 days, that day is not guaranteed if they realize they don't have the staffing to cover it, they could retract the approval. again, I'm not saying it would happen but it could. if both requests came at the same time, military is guaranteed therefore that would be allowed and if staffing does not exist the spot leave would be denied regardless if it were first or second.
spot leave is anything that is outside of the pre-determined guaranteed slots, even if the request comes in march well after the fact as described above it is technically considered NPTL.