EDIT: I believe I have kicked a hornet’s nest. Did not expect this to blow up! But I am still looking for the “ur time”. the basis for it all. Like, maybe the big bang, or something.
In: 5399
the length of a second is defined by about 450 atomic clocks placed all around the world and there are 86400 seconds in a day. the atomic clock solved the problem if precise timekeeping, but it doesn’t solve the problem that the earth simply does what it wants with regards to it’s unpredictable wobbling so sometimes it rotates fast and sometimes it is slow. we solved this by getting humanity together to resync our times every so often. a leap second gets added to one of the days in the year and only on some years, decided by the IERS, which is an organisation with many national members (20+ countries). this is called UTC or universal coordinated time.
anybody can pick a timezone they want which is UTC with an offset, plus or minus any number of hours or minutes and most countries pick a whole number. the UK gets dibs on UTC+0 because as the first global maritime power, they pretty much invented the idea way back when it was called GMT, after the town Greenwich where the Royal Observatory is.
within reason, a country usually picks an offset whereby 12pm for them is where the sun is highest. this means a geographically large country can have multiple time zones (e.g. USA), or they can also force everyone to use one time zone (e.g. China, India). the reason is a weigh off between common sense (people want to work during light and sleep during dark) and commercial/trade (you want to be awake at the same time as your colleagues and trade partners). so almost every country is going to have 12pm slightly off the actual moment when the sun is the highest. if it’s more than an hour off, it’s probably because it’s decided to follow a larger country nearby who it likes to trade with.
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