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UTC Is Enough for Everyone, Right?

zachholman.com

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Re: UTC Is Enough for Everyone, Right?

#31

Post by holman »

zeveb wrote: post #28

> Base ten is lit and doing everything in twelve feels so uncivilized … It's actually the reverse: base twelve is more elegant than base ten[0]. The only reason we think otherwise is that we're used to using base ten. 0: ½ in base twelve is .6; ⅓ in base twelve is .4, not .333333…; ¼ is .3; 1/6 is .2, not .166667

I actually had something similar to this in my notes but didn't get around to adding it. Basically, 60 minutes seems kind of arbitrary for an entire system of time (at least to me!) and then I realized that once you split it down into half, thirds, quarters, etc., it's basically the best numbers to use for informal conversations about time. That was pretty illuminating when I read about that; thanks for pointing it out here!

Re: UTC Is Enough for Everyone, Right?

#32

Post by vikasg »

blunte wrote: post #16

Sadly I didn't have enough time to read the whole article... But I wish we could all just use one time. For some, midday would be 12, and for others it might be 19, but we already all use the same dates regardless of whether February is winter for one location or summer for another.

Software is built for humans to use in the real world. While reshaping the entire world might make the code simpler, it's not a practical solution.

Re: UTC Is Enough for Everyone, Right?

#33

Post by 0x0 »

So the article seems to imply you should store all timestamps as UTC (with an additional timezone string ID). But for events in the future that needs to happen on a specific "wall clock point in time", it might be better to actually store the yyyy-mm-dd hh:mm:ss as a string with a timezone next to it, because timezones can and do change often unpredictably. If you pre-calculate what "4.00pm next August 1st" is as a UTC timestamp today, and the timezone rules are updated between now and then, your UTC timestamp may end up being incorrect. I guess you could have an additional "precalculated-utc-timestamp" column but regularly re-calculate this from the "yyyy-mm-dd hh:mm:ss + timezoneID" (especially when you upgrade your Olson tzdata).

Re: UTC Is Enough for Everyone, Right?

#34

Post by blunte »

snarf21 wrote: post #27
blunte wrote: post #16

Sadly I didn't have enough time to read the whole article... But I wish we could all just use one time. For some, midday would be 12, and for others it might be 19, but we already all use the same dates regardless of whether February is winter for one location or summer for another.

I completely agree. It isn't like we don't deal with this already planning a flight to/from Vegas or having a call with someone on the other coast. Plus we can also get rid of the abomination that is daylight savings. I think there is a simple plan that isn't disruptive. Simply require that all times be listed in both formats. For example, 9:00 am EDT (13:00 UTC) for all printed times on all signs, etc. moving forwar…

Until we get rid of daylight savings times everywhere, dual representations will still require a lot of effort to provide.

Re: UTC Is Enough for Everyone, Right?

#35

Post by Arubis »

vikasg wrote: post #32
blunte wrote: post #16

Sadly I didn't have enough time to read the whole article... But I wish we could all just use one time. For some, midday would be 12, and for others it might be 19, but we already all use the same dates regardless of whether February is winter for one location or summer for another.

Software is built for humans to use in the real world. While reshaping the entire world might make the code simpler, it's not a practical solution.

If I could force everyone on HN to read one comment today, it'd be this one.

Re: UTC Is Enough for Everyone, Right?

#36

Post by madcaptenor »

masklinn wrote: post #24
netsharc wrote: post #15

> This stuff moves a lot, too: the tz database (also known as the Olson database), which is the listing of timezone rules we use as programmers to calm this chaos, gets updated many times a year. Without looking it up, I would say the last change happened when North Korea decided to sync its timezone with South Korea... or have they reverted that since Trump cancelled their summit?

Checking 2018e, that is in fact the last change to the database, though they also updated some past timestamps: > From 1994 through 2017 Namibia observed DST in winter, not summer. > In 1946/7 Czechoslovakia also observed negative DST in winter. 2018d had a change to palestine's DST date (a week earlier than usual), Casey Station moving from +11 to +08 and a few other historical changes/fixes.

To clarify: Namibia had negative DST in (southern hemisphere) winter. They had UTC+1 in the winter (April to September) and UTC+2 in the summer. Now they're UTC+2 year-round, aligned with South Africa. The reason seems to be historical - if you're on year-round UTC+2, and you want to be on UTC+1 in winter/UTC+2 in summer, it's easier to say "we're setting the clocks back an hour in winter" than to say "we're setting the clocks back an hour year-round... and then forward an hour in summer."

Re: UTC Is Enough for Everyone, Right?

#37

Post by blunte »

vikasg wrote: post #32
blunte wrote: post #16

Sadly I didn't have enough time to read the whole article... But I wish we could all just use one time. For some, midday would be 12, and for others it might be 19, but we already all use the same dates regardless of whether February is winter for one location or summer for another.

Software is built for humans to use in the real world. While reshaping the entire world might make the code simpler, it's not a practical solution.

Indeed it simplifies software, but it also makes life much easier for humans trying to coordinate communication across timezones.

There's probably some research somewhere estimating the cost to business (or loss of revenue) from mistakes in doing timezone conversions. In the simplest case, if you have a business call with someone halfway around the world, and one of you has recently gone into or out of daylight savings time, then there's a good chance the call will not happen when it should. Or perhaps you were supposed to be watching a political debate online at a given time so you could provide instant advice and feedback to advisors present in the debate, but you missed it because you didn't realize they had left DST a week before your location does.

I could go on and on with examples of the human cost to keeping the current system.

Re: UTC Is Enough for Everyone, Right?

#38

Post by milesvp »

pquerna wrote: post #29

Love this article, but one thing it skipped on was more in-depth on Leap Seconds. You see, UTC, is kinda like another human-made-up timezone. Humans made up some rules, and UTC is a 37 second offset from TAI / International Atomic Time: https://en.wikipedia.org/wiki/International_Atomic_Time

Right? And that that 37 second offset will change from year to year? I was waiting for the bombshell, that some minutes actually have 61 seconds in them, and some have 59 seconds (though it occurs to me that I don't know if astronomers ever add or subtract more than a second for any given clock adjustment).

Re: UTC Is Enough for Everyone, Right?

#39

Post by captaincrowbar »

blunte wrote: post #16

Sadly I didn't have enough time to read the whole article... But I wish we could all just use one time. For some, midday would be 12, and for others it might be 19, but we already all use the same dates regardless of whether February is winter for one location or summer for another.

"You advocate a ________ approach to calendar reform..." https://qntm.org/calendar
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