Hello!
We completely trust you, just take note of the time you started, and send your final build 7 days after that.
So if you start on Saturday, 1:23 PM, you gotta submit your game before next Saturday, 1:23 PM.
However, if you start along the week, say Wednesday 7:03 AM, you still gotta send your game before Sunday, 11:59PM (That's the only exception to the rule!)