7 ms·
How 1927-12-31 23:54:08 happened twice
- ck2 14y agoAre there any timezones left in the world that do not use whole hours?
- Gurrewe 14y agoYes, there is. http://en.wikipedia.org/wiki/Time_zone#List_of_UTC_offsets http://en.wikipedia.org/wiki/Time_zone#List_of_UTC_offsets
- tellarin 14y agoInterestly quite a few use 30min and three use 45min, but none uses 15min. I wonder why...
- lostlogin 14y agoMight be revealing a profound misunderstanding, but isn't that just because of the reference point? If UTC+0 were the The Chatham Islands, then a few would.
- Dylan16807 14y agoAnd then there would be a gap at 45. The point is that only three of the four quadrants are occupied.
- lostlogin 14y agoYeah that isn't covered by what I said. I wonder if it relates to convenience. Having the same time as your neighbour is probably more handy than having a day that is off by 15 in my opinion, even off by 30 wouldn't bother me much. There must be countries that have muddled through this scenario. But it still leaves a question as to why only certain time points are chosen and others avoided.
- ColinWright 14y agoMany, some use half hours, and there are three that use 45 minutes.
- damian2000 14y agoCentral Australian time comes to mind - GMT+9.5 hrs ... Adelaide, Darwin, Alice springs.
- archangel_one 14y agoChatham Islands, east of New Zealand, are GMT+12:45.
- ghoul2 14y agoOh, the big one: The entire country of India, with all its 1.2 Billion people, is on +5:30
- parimm 14y agoIndia uses UTC +5:30
- jonskeet 14y agoOh there are plenty of time zones which aren't "on the hour". But most of them either don't observe DST or are unimaginitive about it. I was far more impressed by Nepal's proposal (later dropped, I believe) to have a 1:15 daylight saving transition: http://www.timeanddate.com/news/time/nepal-daylight-saving-time.html http://www.timeanddate.com/news/time/nepal-daylight-saving-t...
- goodcanadian 14y agoIt has been pointed out that there are many, but no one has explicitly mentioned Newfoundland (UTC−03:30). That has always been the most familiar to me as when I was growing up, television programs would always be advertised with a time such as "9:00pm (9:30 in Newfoundland)."
- jamie_ca 14y agoNot to mention a couple of times an hour while listening to CBC Radio "It's now 9:12, or 18 to the hour in Newfoundland."
- m4tthumphrey 14y agoJust one of Skeets masterpieces!
- EnderMB 14y agoThe second I read the title and noticed it was a Stack Overflow question, I knew that there would be an answer from Jon Skeet. I'm not usually prone to hero worship, but I've got a lot of time for him. His book C# in Depth is absolutely fantastic, he's helped me (and probably many others on here) with questions on SO, and he comes across as such a nice guy.
- junto 14y agoThere is a really great Scott Hanselman podcast where he invited Jon Skeet on to chat at CodeMash. Fascinating insight into how the guy ticks: http://www.hanselminutes.com/302/being-a-phony-with-jon-skeet http://www.hanselminutes.com/302/being-a-phony-with-jon-skee...
- bxbb 14y agofor a longer, funnier, and mind-blowing explanation from Jon Skeet about time: http://msmvps.com/blogs/jon_skeet/archive/2009/11/02/omg-ponies-aka-humanity-epic-fail.aspx http://msmvps.com/blogs/jon_skeet/archive/2009/11/02/omg-pon...
- mmariani 14y agohttp://www.panic.com/blog/2009/12/on-calendars/ http://www.panic.com/blog/2009/12/on-calendars/ Another interesting post about the weirdness of calendars.
- ubernostrum 14y agoWow, what a coincidence that someone curiously hit precisely the timestamp of this, and knew to use a site where question and answer would be rewarded with attention and votes. (I am coming around to a suspicion that a lot of "wow, that's cool"-type SO questions/answers are more or less fabricated to show off something the person knows, rather than genuine knowledge-seeking, in case you can't tell)
- mdmarra 14y agoJon Skeet (the person that answered the question) works for Google, has more than one blog, and rep caps on stackoverflow daily from old answers because he's answered so many questions there. He's written multiple books on Java and C#. He's plenty visible. Not to mention that the question is over two years old. There's no conspiracy here.
- threegorges 14y agoPlus, if you look at the guy who asked the question, he's a programmer from China, so it's not hard to imagine that had something to do with the fact that these dates popped up in development.
- caf 14y agoIt's considered perfectly legitimate on SO to ask and answer your own question, so there would be no need to use seperate accounts. I can imagine that a question like this could arise as a narrowed-down test case for a bug found in production.
- krallin 14y agoThere's even a feature where you can post the question and the answer at the same time now I believe!
- ig1 14y agoIf you're working with historical time-series data you could easily be doing millions of time comparisons. so it's almost inevitable that people are going to hit edge cases like this.
- dreen 14y agoThis reminds me, if you're near a *nix termial, go and type: cal 9 1752 (dont worry `cal` just shows you a calendar). You can also use this to troll developers that are doing anything that has a calendar.
- obituary_latte 14y agoHeh, interesting. Thanks for the nugget! >The Gregorian reformation was adopted by the Kingdom of Great Britain, including its possessions in North America (later to become eastern USA), in September 1752. As a result the September 1752 cal shows the adjusted days missing. This month was the official (British) adoption of the Gregorian calendar from the previously used Julian calendar. This has been documented in the man pages for Sun Solaris as follows. "An unusual calendar is printed for September 1752. That is the month when 11 days were skipped to make up for lack of leap year adjustments." The Plan 9 from Bell Labs manual states: "Try cal sep 1752." [0] [0] http://en.wikipedia.org/w/index.php?title=Cal_(Unix)#Features http://en.wikipedia.org/w/index.php?title=Cal_(Unix)#Feature...
- mirkules 14y agoSome Orthodox Christians still use the Julian calendar, if only symbolically, so Christmas falls on January 7th and New Years on January 14th (Easter is a much different story: http://christianity.about.com/od/faqhelpdesk/qt/whyeasterchange.htm http://christianity.about.com/od/faqhelpdesk/qt/whyeastercha...). In theory, these dates should move farther and farther apart than just two weeks from the Gregorian calendar because the Julian calendar doesn't count leap years the same way. For us Julian calendar folks, there's upsides and downsides. We get to celebrate Christmas late, but my kid will celebrate both (since my wife is of a different religion). And of course, Easter falls on Cinco de Mayo this year (but we had remember to buy enough egg coloring well in advance)! :)
- jnuss 14y ago+1 for showing me *nix terminals have a simple calendar command. Awesome.
- jonskeet 14y ago
- pdw 14y agoThis is really not a corner case. Think about it. Every place with daylight saving time will experience a duplicate hour when switching from summer time to winter time. A timestamp given in local time can map to multiple UTC times.
- raldi 14y agoExcept you can remove the ambiguity by stating either PDT or PST. You don't have that option in 1927 Shanghai.
- mortehu 14y agoNote that strftime does not produce unambiguous time zone names. The four-letter Australian time zones are printed with names such as EST and CST. Better use -0500, +0545 and the likes, as suggested by ISO 8601.
- jonskeet 14y agoIf you want to indicate a time zone you shouldn't just use the offsets - they're ambiguous in that several different time zones can have the same offset at any point in time. Better (IMO) to use the zoneinfo ID, e.g. "Europe/London" - along with the offset as well, in case the local time is ambiguous in that time zone due to a daylight saving transition.
- lifeformed 14y agoWould a better system for our society be to just have a universal time? Like, what if everyone in the whole world just set their clocks to UTC+0:00, and never ever changed it. They would just plan everything relative to that. I might work from 9-5 in one place, but in another someone would work from 3pm-11pm (still during daylight hours). That is to say, why do we try to synchronize our numbers with the sunlight? Is it that important that every culture gets to say that 12pm is midday? It does seem weird that it may be customary to eat lunch at 12pm in one place, but have it normal to eat lunch at 4:30am in another. But is it any weirder than having arbitrary discrete jumps in time based on geography and time-of-year?
- ars 14y agoNo, that would not be a better system. You are just pushing the complexity somewhere else. It might make computer programming a bit easier, but everything else would be harder. And people still sleep at night, so you would still need to know when they are awake, when they work.
- lifeformed 14y agoIt wouldn't be easier just for computing. If I need to coordinate stuff with someone in a different time zone, it'd be much easier to be able to just say "Let's have a call at 4pm," instead of figuring out what his timezone is. I guess you'd still have to know if 4pm is a good time for him though. So he'd have to have some sort of indicator of what the waking/working hours are in his region... some sort of time zone. Nevermind, the more I think about it the more I realize that timezones are pretty reasonable.
- ars 14y agoLOL, I was about to reply exactly that, then you answered your own question.
- dragonwriter 14y ago> You are just pushing the complexity somewhere else. It might make computer programming a bit easier, but everything else would be harder. It would make communicating times easier and less prone to confusion. > And people still sleep at night, so you would still need to know when they are awake, when they work. Right, you would need to know when the particular people you are dealing with would be available, but when communicating times to coordinate an event, the numbers used would have the same meaning. I don't see where any complexity is being added to compensate for that that is being lost.
- Mahn 14y agoOdd, I would think most HNers have already heard of the top voted Jon Skeet answer. This is really old. Discussion is always great though, can't question that.