I will readily admit if someone can show that I am wrong in principle, but in application I am 100% correct. Scheduling will code a LC into XX GS more than 18 hours to report as F every single time. That is the only scenario under disagreement.

GS on all X days: G code all above guarantee

GS that starts on X day(s) and goes into LC day(s): G code with duty day(s) on X days paying above guarantee and on LC days going towards guarantee.

GS all on LC days with less than 18 hours to report: F code, only first duty period above guarantee

GS all on LC days more than 18 hours to report: not sure this is really applicable since this should be a LC assignment.

GS that starts on LC day(s) and spills into X day(s) with less than 18 hours between award and report: F code, first duty period on top of guarantee plus any applicable duty periods over X days.

GS that starts on LC and ends on X days with more than 18 hours between award and report: under dispute.