I logged into the game and had over 17 hours before the timers were reset according to the "Timers" window available in the main menu. I proceeded to gather all of the items for the timer that I wished to turn in. Upon my return to the Grand Company the requested items had changed. I opened up the Timers window again through the main menu and it still read 16:27 mins before they changed. The conclusion drawn is that the actual reset is occurring independently of the scheduled time causing efforts made to need to be redone to adjust to the altered completion requests.