While 2 rounds of 12 hrs or 1 round of 24 hrs are considered standard acceptable divisions of time across the world, there are and have been some different alternatives to this throughout human history.

[THREAD] https://twitter.com/LlamaInaTux/status/1390034663494668291

Until a few centuries ago, the Romans followed a clock that divided the day into 4 quarters of 6 hours each. The day started with the evening Hail Mary (Catholic prayer) immediately after sunset. The day was divided into four parts to regulate the monastic hours of prayer.

Egyptians used to measure their time using sundials where the hours were a flexible unit that varied with seasons depending on the length of day and night. So 12 day hours in a summer season was a longer time than in a winter, with the night hours being a longer time in a winter.

Some Hindu customs divided the day and night equally into 4 prahars each. This would make each prahar about 3 hours long. The Hindi word dopahar (afternoon) is also derived from this division and translates to 2 prahars - the 6 hour time period before sunset.

Alternatively, some Hindu customs divide the day into 30 muhurts each. This would make each muhurt about 48 mins long. A muhurt is also part of an elaborate Hindu astrological belief that attempted to determine the age of universe and the role of humans within it.

Japan practices a unique 30 hr clock system where while 24 hrs are counted as normal time, the 6 hrs past midnight are often added on to the previous day's time to make it feasible for people awake at that point. So trains can begin their journey at 23:15 and end it at 24:30.

This causes a period of 6 hrs post midnight where 2 different times overlap. One that has begun for the following day at 00:00 and the other going from 24:00 to 30:00 for the previous day.

So it's fair to say there's no one way to look at time. It's fascinating in a way how different cultures arrive at these conclusions due to differing philosophies about life and the demands of the era they lived in.

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