The timer for grand company turn ins is wrong, or rather it's wrong in all but 1 time zone. The reset actually happens at 4:00 PM EDT I believe. Not sure which time zone you're in, but this should be helpful. I have no idea why the timer is not actually linked to when the supply missions reset, but it's been like that for as long as I can remember so I just keep in mind that it resets at 4 PM (for me).