Originally Posted by Verdell

This doesn't check. I see 2 scenarios:

1) You previously had acknowledged your 1200 SC during your X-day, after which you enter rest 18 hours prior to the start of that SC.

2) You had not previously acknowledged your 1200 SC, in which case your rest is interrupted at the stroke of midnight when your LC begins, at which point you go directly back into rest for your 1200 SC.

Under neither scenario were you on LC for a 1200 SC between midnight and 1AM of the same day.

HOWEVER, it is at scheduling discretion to deny a GS that would wipe out a same-day RES assignment. They didn't HAVE to give you the GS that morning. That part checks, but the explanation they gave you doesn't.