The Chinese kè

How to read it

The day is divided into one hundred kè (刻), counted here from midnight. One kè is 14 minutes and 24 seconds. The bar fills as the current kè passes, and the number above it says how many whole kè have gone by today.

A hundred kè do not fit evenly into the twelve double hours that were kept alongside them, so a kè boundary rarely lines up with an ordinary hour. At noon, 50 kè have passed.

Where it came from

The name means a notch or mark: the kè were the marks on sundials and on the floats of water clocks.¹ By the first millennium BC the day was already divided into 100 kè, alongside the twelve double hours.²

The hundred did not quite divide into twelve, and for a few short periods the count was changed to 120, 96 or 108 kè a day.² In the seventeenth century it settled at 96, which made each kè exactly a quarter of an hour; the sources disagree on the year, giving 1628 and 1645.^{1, 2}

Sources

1. Ke (unit) (Wikipedia, CC BY-SA 4.0)
2. Decimal time (Wikipedia, CC BY-SA 4.0)