Timey-wimey went all wibbly-wobbly

Every now and then, I find there isn't a lot I can say to explain or pad out the details of a Gem. This is one of those occasions.
Essentially, there was a little confusion over what the time was, and Julie had read a clock wrongly. Unfortunately, her reasoning for her failure was rather more 'fail' than 'reason'...

Even now, neither of us can work out just what she meant.