Before going to bed on Sunday night, I set the alarm clock for 6:40. (On the weekends, I tend to set it for a little later, so on Sunday I have to set it back to my weekday schedule.)

I woke up this morning and after a few moments started wondering if I’d somehow awoken before the alarm. It’s been known to happen, but given how late it was by the time I actually fell asleep (around 3:30 or 4:00), that didn’t seem too likely.

So I pried myself out of bed and looked at the clock.

8:24

Oh crap.

(Actually, the phrase that went through my mind was not “oh crap”, but it did contain the same number of letters .)

The indicator showed that the alarm was definitely set. Had I slept through it? (This has also been known to happen, particularly when I’ve had trouble falling asleep the night before.)

For whatever reason, I pushed the button to check what time the alarm was set to go off.

It was set for 6:40 alright. But here’s the interesting part: it turns out there are two 6:40s in the day, and they’re not equivalent.

Who knew?