10:01, mirror hour
Ten oh-one: 10:01, where the digits of the hour (1, 0) appear in reverse order in the minutes (0, 1). A quiet morning reversal, easy to overlook if you are not watching the full four-digit display.
The digits add up to two, the number that implies a second half somewhere. It suits an hour you almost miss. One minute past ten the morning is already under way and nobody announced it, which is usually what a thing on its right track sounds like. Quiet. Checked once, then left to run.