There were a few e-mail messages on the FtB backchannel a little while ago. An FtB blogger who lives in Ireland was wondering when the next FtB Podish-Sortacast will happen (https://freethoughtblogs.com/pharyngula/2024/03/09/in-my-prime/, scroll down a bit), probably just under an hour from when I get this posted.
That got me to thinking about civil time in the Irish Republic. It winds up that they observe the same time as Great Britain and Northern Ireland, except they get there with rather tortured reasoning.
In the U.K., they switch from “Greenwich Mean Time” (GMT, same as UTC+0) to “British Summer Time” (BST, UTC+1) on the last Sunday in March at 01:00:00 local wall clock time, and they switch back from BST to GMT on the last Sunday in November at 02:00:00 local wall clock time.
In Ireland, they switch from ”Irish Standard Time” (IST, UTC+1) to GMT on the last Sunday in November at 02:00, and they switch back from GMT to IST on the last Sunday in March at 01:00.
Yes, really. Go figure. 😎
The POSIX TZ environment variable for Europe/London: GMT0BST,M3.5.0/1,M10.5.0
The POSIX TZ environment variable for Europe/Dublin: IST-1GMT0,M10.5.0,M3.5.0/1
Why did they bother?
Just in time to celebrate the changing-of-the-clocks, the local and national news featured stories about how bad this is for everyone’s health and how losing an hour of sleep is very, very bad for an already-sleep-deprived population. More car accidents happen because people are so sleepy and disoriented, more people than usual suffer health events like heart attacks and strokes, etc. etc.
Mr, Seymour, thanks for the C++ explainer for my int six=6 thing.
Spring Forward, Fall Back is an easy way to remember the direction of the time shift. I rather prefer the Fall Back part. That got my thinking running well off the beaten path into unlikely scenarios.
Why not fall back in both spring and fall? This would match my preference, above. Then maybe it could do away with leap days. Thinking … … Okay, for no more leap days we would have to fall back 6 times a year. After 4 years a full 24 hours would make leap years an historical artifact. An extra or withheld Fall Back hour could be applied as needed to keep the seasons matching the calendar. This can’t be much stranger than leap milliseconds.
By the time the world starts doing this, every place in the world could be using only one time zone. GMT+0 for everybody! C++ time zone math would be unnecessary.
I wouldn’t get rid of time zones. Yes, some people sometimes get a bit confused on how to figure out what time it is in some place far away; but most folks are more interested in when the sun is up in their own neck of the woods.
There are certainly improvements we could make, though. For example, back in 1973, Isaac Asimov came up with what he called the “world seasonal calendar”. He kept 7-day weeks because so much of our culture is based on that; but he got rid of months, proposing instead four seasons of 13 weeks each. That comes to 364 days, so every year would have a “year day” and roughly every fourth year (minus a few century years) would have a “leap day”. Year day and leap day wouldn’t be days of any week, and so every season would start on the same weekday. It wouldn’t take long before everybody would know immediately what day of the week it was given the date.
I always thought that was pretty cool.
Hi Bill. Have you seen this question on Stack Overflow about subtracting two times in 1927? It has one of the highest-voted answers ever:
https://stackoverflow.com/questions/6841333/why-is-subtracting-these-two-epoch-milli-times-in-year-1927-giving-a-strange-r
Enjoy. 🙂
bythescruff @4: no, I hadn’t seen that; but then ever since my retirement I’ve successfully avoided paying any attention to Java (except maybe for some lulz, e.g. (an older one from when I was still gainfully employed), RomanNumeralFormat.java).
My personal favorite example of civil time weirdness is what happened when the United States bought Alaska from Russia in 1867: the international date line moved from the Alaska-Canada border to the Bering Strait; and October 6 in the Julian calendar (which Russia was still using for religious reasons) was followed by a second instance of the same day with a different name, October 18 in the Gregorian calendar. 😎