almost two weeks as of now but at the time of your posting it was only up for just 3-4 days. I know about fate grinding, and turning in HQ in Leve quests and other fast track tricks but to reach that many in just 3-4 days even playing 24 hours that's, speechless.
Did an FC help you out with mats? because you would also need to level gathering and that is slow and boring, not to mention you couldn't do that many leve's as you don't collect that many in under 4 days.