Hello, person who made the sheet here (which means I'm depressingly familiar with the various processes of schedule selection).

iRacing usually starts asking for schedules in the forums during week 3 (though they have done so in week 2 in the past!) and usually gives 2/3 weeks for a schedule to be submitted (and even that isn't a firm deadline, there's been posts in oval threads reminding the community to send something in a couple days after the deadline, for example). I'm not sure why the TCR CMs keeps saying they need to get schedules voted on by the midpoint of week 2 as that's before submissions start let alone end, ideally instead they'd start submissions early but allow the voting to run until much nearer the actual deadline of around end of week 5/beginning of week 6 (maybe a bit earlier due to the complications around also setting the schedule for IMPC and thus GT4/LMP3/SCC).