Lol, this is a plausible theory. I like it!
Wait... I've only found 2 clocks in the open world... There may be a third though, I haven't done a thorough search. If we can pinpoint the locations of all 3 clocks, and those clocks happen to form a triangle, then we go to the centre of the triangle and see what's there.I thought I was onto something with the clock, but I think it's a dead end.
The only clock I could come across was at Twin Coyote Arcade, but as I was flying through the city, I noticed a giant version of the same clock on the front of a building, with the same time on it... And the time never changes on either one, so I don't know if it means anything or not.