Originally Posted by B1indSide
I did it Tuesday morning between 6:30 - 7:00 AM U.S. Eastern Time.
I switched the clock back and forth between -12 Tokelau (Mon 10:30 PM) and +14 Kiribati (Wed 12:30 AM).
Change your clock in the console settings to one of the above. Load the game to the menu, then quit to dashboard. Change the clock to the other time and reload the game. Rinse and repeat.
So change your clocks to -12 and figure out which day and time just after 10 PM will be on a Monday and do it twelve to fourteen times and you should get it
UPDATE: I got to thinking and I'm worried that those of us that got it, just got lucky we were doing it at the end of the month and that it was switching between Sept. 30 and Oct. 1. So not only was the day changing, but the month, too. So loading the game twice counted as 1 month (sept - oct - back to sept), which is why some people say they got it after 7 tries. So you might have to do it at the end of a month so it switches between two months rather than between a monday and tuesday.
This is NOT certain but I will feel terrible if someone waits till next monday and doesn't get it, so PLEASE, if anyone tries it next monday, post your results after giving it at least 12 or so tries. Thank You!
I can confirm this to work. Only took about 15 minutes (I wasnt counting tries)