You know that test in elementary school that has dozens of steps for filing out a form and then the last step is ignore all previous step and return the blank form? I always fail that test...
Expect a land rush, so accurate clocks, alarm setting and game play must be considered as editing your pick after placement is still not allowed.
In your case, you trusted an inaccurate clock. I've seen cell phone clocks be off by as much as 75 seconds, in spite of the fact that they get their time from the cell network which is supposedly GPS synced .