Time feels like the most objective thing there is, right up until you ask where any of it comes from. Then it turns out your wristwatch is running 4,000-year-old Babylonian math and the calendar once misplaced eleven entire days. Thirteen questions follow. Commit before each reveal, keep score, and try not to think too hard about what “now” means.

Round One: Why the Clock Looks Like That

Start with the question hiding in plain sight. Why are there 60 minutes in an hour and 60 seconds in a minute — why not a tidy 100? Credit the Babylonians, who inherited a base-60 counting system from the Sumerians. And 60 is a genuinely superb number for the job: it divides evenly by 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30, so you can halve it, third it, and quarter it without fractions. Base-60 lost the war for arithmetic but won the clock — and the 360-degree circle, while it was at it.

Next: why 24 hours in a day? The ancient Egyptians divided daylight into 12 hours and night into 12 more. Why twelve? One leading theory points at your own hand: count the finger joints on four fingers using your thumb as a pointer and you get exactly twelve. The clock on your wall may be a fossilized finger-counting trick.

Now the seven-day week. Here's the uncomfortable truth to lock in before reading on: is there any astronomical reason for it? No. Unlike the day, month and year, the week tracks nothing in the sky — it's pure inheritance, from Babylonian tradition and the seven classical “planets” visible to the naked eye: the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn. English still wears three of them openly — Sun-day, Moon-day, Saturn-day — and the Romance languages kept most of the rest.

Round Two: The Calendar Loses Its Mind

Quick etymology check: what do September, October, November and December literally mean? Seventh, eighth, ninth and tenth month — which is off by two, because the early Roman year began in March. The names never got fixed; we've all just agreed not to make eye contact with the problem for two thousand years.

Now the headline event. In September 1752, Britain and its American colonies went to bed on Wednesday the 2nd and woke up on Thursday the 14th. Where did the eleven days go? Nowhere — they were skipped on purpose, as Britain finally switched from the drifting Julian calendar to the more accurate Gregorian one, 170 years after Pope Gregory XIII introduced it in 1582 (Catholic countries had skipped ten days back then; Britain's lag cost it an eleventh). The famous tale that mobs rioted demanding “give us our eleven days!” is, historians now largely agree, an exaggeration built on a satirical Hogarth painting — the honest version is grumbling, not riots.

The switch produced one great side effect worth a point on its own: George Washington's birthday moved. Born February 11, 1731 under the old calendar, he became — after the conversion, plus England's simultaneous decision to start the year in January instead of March — a February 22, 1732 baby. Same man, new birthday, different year, no time travel involved.

Round Three: Leap Everything

You know leap years happen every four years. But lock in the full rule: was 1900 a leap year? No — and 2000 was. Century years only leap when divisible by 400. That correction is the entire genius of the Gregorian calendar, and it's why your calendar won't drift a full day against the seasons for thousands of years.

Smaller and stranger: what is a leap second? Since 1972, official atomic time has occasionally added a single extra second — 27 of them so far, most recently on New Year's Eve 2016 — because Earth's rotation is slightly irregular and doesn't match the atomic clocks' perfection. Two glorious wrinkles to finish: the world's timekeepers voted in 2022 to retire the leap second by 2035, because it keeps breaking computer systems; and Earth's rotation has lately been speeding up, raising the prospect of something that has never happened — a negative leap second, where the clocks skip one instead.

Final question, small but satisfying: why is February the short month? The standard account traces it to the early Romans, who considered even numbers unlucky and gave their months 29 or 31 days — February, assigned the year's leftover days at the tail end of winter, absorbed the shortage and never recovered.

Count your score. If you got the finger joints, the fake riots, and the negative leap second, you're operating comfortably ahead of schedule — by at least eleven days.