• Brendan (unregistered) in reply to Therac-25
Therac-25:
What other solutions are there for the problem? i.e. the rotation of the earth is not in perfect sync with it's orbit, so you can't create a measurement of the orbit that is perfectly factored by a measurement of it's rotation.

My theory is that by firing Perl developers into orbit using a high speed cannon facing west, we could increase the rotational speed of the earth (Newton's third law) and end up with 29 days in February every year. This would solve at least one problem, and might also solve the leap year problem too.

• Ron (unregistered) in reply to Gurth

That's okay... I noticed in the date/time on Android 4.0, if you advanced the date from 2/29, it would change to 3/1 correctly. Now if I rolled it back one day, you'd see the date 2/30 appear briefly as the date numbers rolled, then it quickly switches to 2/29....

• anon (unregistered) in reply to Y2K

[quote user="Y2K"]I suspect most programs got "lucky" in Y2K./quote]

Nah - there's a 200-year window from 1900 to 2100 when the exceptions for 100/400 years don't apply, so most of the time there's no need to worry about them.

• (cs) in reply to PiisAWheeL
PiisAWheeL:
Bernard Kerckenaere:
That depends on the number of leapyears there's in those past 21 years.

I think I calculated for it. 21365.25246060*1000=662709600000

As I understand things, the Unix timestamp counts seconds, not 1000's of them. See time(2). Of course, one uses hex: 0x27802560

• (cs) in reply to ContraCorners
ContraCorners:
Set a reminder for yourself now, so you don't forget. On 2013-03-01, set your watch back a day. I'm curious to see whether it goes back to the 28th or 29th.
I can say with a fair amount of confidence that it would, because the watch doesn't store the year at all. Of course, I knew this, really, because I have had to set the correct time and date several times before (after changing the battery, for example), but it's not something I consciously think about all the time :)

On a watch that does track the year, you could easily test this by setting the year to 2013 without needing to wait a whole year.

• Jasper de Vries (unregistered) in reply to Mason Wheeler

And the Daylight Savings Time changes. Twice a year, you can set the clock by it.

• Mary (unregistered) in reply to Gurth

Storing the date is boring - detecting a "decrement date on the first of March" is cunning. Which would any programmer prefer to implement?

• Virgil (unregistered)

• (cs) in reply to anon
anon:
There's a 200-year window from 1900 to 2100 when the exceptions for 100/400 years don't apply, so most of the time there's no need to worry about them.
Actually, it's not that they don't apply but rather that they both apply. (I remember this being discussed in nauseating detail in 2000 by people who should have known better. The real rule is “leave it to experts to write time handling libraries”; anything else is TRWTF.)
• (cs) in reply to pjt33
pjt33:
frits:
This makes me wonder why the Euros are all pushing for a metric calendar.
We are?
Of course, everybody knows that all Europeans are lazy bums that couldn't defend their own country against an invasion of toddlers armed with Teletubby soft toys. We all get six months of paid holidays a year, so if we go to 10 instead of 12 months a year, we get more holidays. Yo! Party!
• Stappie (unregistered) in reply to Mason Wheeler

...and time zones.

• Cbuttius (unregistered)

We should change the calendar to have 365 days every year, then a leap-week periodically. That way you don't lose a birthday falling on a particular day of the week. I lose my Friday birthday this year and am also in my 11-year wait between Sunday birthdays and Wednesday ones given my last of those was in 2010 and the next in 2021.

The obvious time to put in the leap week would be after 28 years, however due to the "shift" we would actually have it every 29 years.

This would make the average year 365.24138 days long. At present it is 365.2425. Not sure what the "perfect" figure would be, but it being slightly shorter than 365.2425 may reduce the need for leap-seconds too.

Of course those who currently have birthdays on 29 February would not get birthdays anymore, and those born in the leap week would only get one every 29 years. We can't please everybody. But it would be nice not to have to wait until 2021 for the next time my birthday will fall on a Wednesday.

• Cbuttius (unregistered) in reply to Cbuttius

The last year that was divisible by 29 was 2001. The next will be 2030. So those would be our leap years.

• (cs) in reply to frits
frits:
This makes me wonder why the Euros are all pushing for a metric calendar. I mean the Leap Year problem is a pretty good example why the Gregorian Calendar should be considered harmful.

That is utterest stupidest nonsense I have heard in my entire life.

• Hmmmm (unregistered) in reply to Nagesh
Nagesh:
That is utterest stupidest nonsense I have heard in my entire life.

You must be new here.

• Sam (unregistered)

The fun really starts when big systems like Microsoft Azure have a worldwide outage due to leap year problems (which, coincidentally, just happened yesterday).

• Sam (unregistered) in reply to frits
frits:
This makes me wonder why the Euros are all pushing for a metric calendar. I mean the Leap Year problem is a pretty good example why the Gregorian Calendar should be considered harmful.

Yeah, sure. And we still run around naked, hit each other with clubs and live in caves.

Funny to see how some people have no clue about the world :)

• Tractor (unregistered) in reply to geoffrey, MCP, PMP
geoffrey:
Big deal. So the site doesn't work one day every four years. There are more important things to deal with in any enterprise.

Actually, failing once every 4 years, excluding every 100 years but then failing again every 400 years.

But that's not the point, it shows that too many Enterprisey systems re-implement things that are readily available, an do so faultily (yes, that's a word). If you find yourself molesting numbers to get the date you want, that's a sign you need read up a bit on the language or platform you're using.

• TheJonB (unregistered) in reply to Therac-25
Therac-25:
frits:
This makes me wonder why the Euros are all pushing for a metric calendar. I mean the Leap Year problem is a pretty good example why the Gregorian Calendar should be considered harmful.

What other solutions are there for the problem? i.e. the rotation of the earth is not in perfect sync with it's orbit, so you can't create a measurement of the orbit that is perfectly factored by a measurement of it's rotation.

Don't worry about it, time can be entirely abstract. We could easily have a 100 week year that normally has two winters.

• Nick (unregistered) in reply to Mason Wheeler

TRWTF is the ridiculous and confusing MM/DD/YYYY format. DD/MM/YYYY ok YYYY/MM/DD ok but MM/DD/YYYY? No no no!

• Level 2 (unregistered) in reply to Nagesh-saki
Nagesh-saki:
This should be a holiday

(There is a f-word I am missing)

Free holiday would be a pleonasm.

• Miguel Farah (unregistered) in reply to PiisAWheeL
PiisAWheeL:
Bernard Kerckenaere:
That depends on the number of leapyears there's in those past 21 years.

I think I calculated for it. 21365.25246060*1000=662709600000

More like 662709600011... you forgot leap seconds.

Nick:
TRWTF is the ridiculous and confusing MM/DD/YYYY format. DD/MM/YYYY ok YYYY/MM/DD ok but MM/DD/YYYY? No no no!

Actually, MM/DD/YYYY is the only correct way because it is how people actually say dates. Ask someone when Christmas is and see how many say December 25 vs. 25 December. Then people throw in the year last if it is necessary.

Nick:
TRWTF is the ridiculous and confusing MM/DD/YYYY format. DD/MM/YYYY ok YYYY/MM/DD ok but MM/DD/YYYY? No no no!

Actually, MM/DD/YYYY is the only correct way because it is how people actually say dates. Ask someone when Christmas is and see how many say December 25 vs. 25 December. Then people throw in the year last if it is necessary.

Christmas? 25th of December!

At least, that's been my experience.

• Doug (unregistered) in reply to Gurth

Mine does exactly the same thing. I guess the manufacturer doesn't want you to bitch about going through all of the days of the month to get to the 29th every four years.

• (cs) in reply to Hmmmm
Hmmmm:
Nagesh:
That is utterest stupidest nonsense I have heard in my entire life.

You must be new here.

XD

Nick:
TRWTF is the ridiculous and confusing MM/DD/YYYY format. DD/MM/YYYY ok YYYY/MM/DD ok but MM/DD/YYYY? No no no!

Actually, MM/DD/YYYY is the only correct way because it is how people actually say dates. Ask someone when Christmas is and see how many say December 25 vs. 25 December. Then people throw in the year last if it is necessary.

YYYY-MM-DD is the only one that sorts properly and that's why it's the standard (ISO 8601). Anyone who uses anything else is the kind of person who becomes a featured article here.

Nick:
TRWTF is the ridiculous and confusing MM/DD/YYYY format. DD/MM/YYYY ok YYYY/MM/DD ok but MM/DD/YYYY? No no no!

Actually, MM/DD/YYYY is the only correct way because it is how people actually say dates. Ask someone when Christmas is and see how many say December 25 vs. 25 December. Then people throw in the year last if it is necessary.

YYYY-MM-DD is the only one that sorts properly and that's why it's the standard (ISO 8601). Anyone who uses anything else is the kind of person who becomes a featured article here.

Dates aren't FUCKING STRINGS!

• Russell (unregistered)

My web hosting service, Web.com, had two consecutive days of Feb.28th. Some of my newest files ended up looking like they were created earlier than their prior versions. When are humans going to be perfect?! Exasperating.

• Nagesh (unregistered) in reply to Nagesh
Nagesh:
frits:
This makes me wonder why the Euros are all pushing for a metric calendar. I mean the Leap Year problem is a pretty good example why the Gregorian Calendar should be considered harmful.

That is utterest stupidest nonsense I have heard in my entire life.

India is second-world country.

• Raplh (unregistered) in reply to TheJonB
TheJonB:
YYYY-MM-DD is the only one that sorts properly and that's why it's the standard (ISO 8601). Anyone who uses anything else is the kind of person who becomes a featured article here.
Dates aren't FUCKING STRINGS!
YES THEY FUCKING ARE!

Some files on a shared folder on our network drive:

April 2011.docx August 2011.docx December 2011.docx Feb 2011.docx January 2012.docx July 2011.docx June 2011.docx Mar 2011.docx May 2011.docx November 2011.docx October 2011.docx September 2011.docx

Notice how nicely they sort! (NOT)

• (cs)
herby:
PiisAWheeL:
Bernard Kerckenaere:
That depends on the number of leapyears there's in those past 21 years.

I think I calculated for it. 21365.25246060*1000=662709600000

As I understand things, the Unix timestamp counts seconds, not 1000's of them. See time(2). Of course, one uses hex: 0x27802560
You win. I get 1000's of a second when I ask unix for a timestamp. It never occured to me that it doesn't actually store the 1000's.

So we will go with 662709600 for the purposes of deciding if you can visit an over 21 website. Give or take 4 hours. Then round down (backwards) to the nearest midnight. That should keep government regulators happy.

Franco:
Simon:
Joe:
Why not simply adjust the Earth's orbit inward slightly so that it completes an orbit in exactly 365.0000 days?

If you're going to do that, can I suggest going with the slightly more readily divisible 360 days? And adjusting the lunar orbit appropriately so months can all be of equal length?

The easiest way is to change the speed of the rotation, and not translation, of earth. Perhaps if 6000mi people would run west bound at the same time, we can do it without too much tech!

Nice in theory... in practice that energy would go back into the planet when they all stopped running.

Changing the length of a year physically (by adjusting the earths orbit) will create big problems. Dates would have to be recalculated throughout history. Any individual dinosaur bone currently carbon dated would be off by about 132710(and some change) years if it were on a dinosaur 200MI Years ago. Hell, my birth day would be off by a few days.

If you fuck with the moon's orbit, you fuck with the tides. I can't possibly see anything going wrong with that one? Can you? The moon also has an effect on the rotation of the earth. You change that and suddenly a day becomes a little bit shorter or a little bit longer. That itself could effect the number of days you get crammed into your year, which would undo or overdo the effect you tried to achieve when you tried to move the earth closer to the sun and set it in a slightly faster orbit.

• Hmmmm (unregistered) in reply to PiisAWheeL

[quote user="PiisAWheeL]The moon also has an effect on the rotation of the earth. You change that and suddenly a day becomes a little bit shorter or a little bit longer. That itself could effect the number of days you get crammed into your year, which would undo or overdo the effect you tried to achieve when you tried to move the earth closer to the sun and set it in a slightly faster orbit.[/quote]

Well, obviously it would be an iterative process with a reasonable delay (say, a few decades or so) between each adjustment of earth or moon orbit to let everything settle back down to a nice equilibrium. No sense in rushing something this important...

• A non mouse (unregistered) in reply to TheJonB
TheJonB:
Nick:
TRWTF is the ridiculous and confusing MM/DD/YYYY format. DD/MM/YYYY ok YYYY/MM/DD ok but MM/DD/YYYY? No no no!

Actually, MM/DD/YYYY is the only correct way because it is how people actually say dates. Ask someone when Christmas is and see how many say December 25 vs. 25 December. Then people throw in the year last if it is necessary.

YYYY-MM-DD is the only one that sorts properly and that's why it's the standard (ISO 8601). Anyone who uses anything else is the kind of person who becomes a featured article here.

Dates aren't FUCKING STRINGS!

One evening I opened my pantry and found the fruit and yarn all intertwined, and I assure you it was no laughing matter.

• Crisw (unregistered) in reply to Carl
Carl:
Now that we are on the verge of becoming a spacefaring civilization, it is long past time to discard our backwater planet-centric timekeeping system in favor of something Universal.

I propose a simple floating point counter of seconds since the big bang. Should work anywhere, forever. Leap second, leap year, Y2K, December 2012... who cares? Just keep incrementing that counter!

How does that handle time dilation at speeds approaching c?

• The Cloud has no Feb 29 (unregistered)

http://blogs.msdn.com/b/windowsazure/archive/2012/03/01/windows-azure-service-disruption-update.aspx

• Hmmmm (unregistered) in reply to Crisw
Crisw:
How does that handle time dilation at speeds approaching c?

I suspect the number of visitors to this site that can reason intelligently about relativity is less than or equal to the number of states that a boolean can have...

• (cs) in reply to Crisw
A non mouse:
One evening I opened my pantry and found the fruit and yarn all intertwined, and I assure you it was no laughing matter.
Is that a banana in your pocket... or some other kind of fruit?
Crisw:
Carl:
Now that we are on the verge of becoming a spacefaring civilization, it is long past time to discard our backwater planet-centric timekeeping system in favor of something Universal.

I propose a simple floating point counter of seconds since the big bang. Should work anywhere, forever. Leap second, leap year, Y2K, December 2012... who cares? Just keep incrementing that counter!

How does that handle time dilation at speeds approaching c?

It doesn't. You will need to do the math to adjust the rate at which your counter increments as you increase in speed.

• (cs) in reply to Hmmmm
Hmmmm:
Crisw:
How does that handle time dilation at speeds approaching c?

I suspect the number of visitors to this site that can reason intelligently about relativity is less than or equal to the number of states that a boolean can have...

2. Tell me, How did you calculate that number?

• (cs) in reply to Hmmmm
Hmmmm:
PiisAWheeL:
The moon also has an effect on the rotation of the earth. You change that and suddenly a day becomes a little bit shorter or a little bit longer. That itself could effect the number of days you get crammed into your year, which would undo or overdo the effect you tried to achieve when you tried to move the earth closer to the sun and set it in a slightly faster orbit.

Well, obviously it would be an iterative process with a reasonable delay (say, a few decades or so) between each adjustment of earth or moon orbit to let everything settle back down to a nice equilibrium. No sense in rushing something this important...

Probably best to try this in a test environment first.
• (cs) in reply to ContraCorners
ContraCorners:
Hmmmm:
PiisAWheeL:
The moon also has an effect on the rotation of the earth. You change that and suddenly a day becomes a little bit shorter or a little bit longer. That itself could effect the number of days you get crammed into your year, which would undo or overdo the effect you tried to achieve when you tried to move the earth closer to the sun and set it in a slightly faster orbit.

Well, obviously it would be an iterative process with a reasonable delay (say, a few decades or so) between each adjustment of earth or moon orbit to let everything settle back down to a nice equilibrium. No sense in rushing something this important...

Probably best to try this in a test environment first.
Thats not very practical... There is no planet in this solar system we could test it on that wouldn't affect earth's orbit... which means we have to find a NEW solar system and then study it for YEARS and THEN we can make the appropriate changes, move the planet and then study it for a LOT more years. I'm down if we solve the aging and the death by aging problem... but you are looking at a MINIMUM of 3 Centuries AFTER we discover faster than light (or wormhole) travel. And that assumes we have done our homework and the financing is all in order.
Nick:
TRWTF is the ridiculous and confusing MM/DD/YYYY format. DD/MM/YYYY ok YYYY/MM/DD ok but MM/DD/YYYY? No no no!

Actually, MM/DD/YYYY is the only correct way because it is how people actually say dates. Ask someone when Christmas is and see how many say December 25 vs. 25 December. Then people throw in the year last if it is necessary.

YYYY-MM-DD is the only one that sorts properly and that's why it's the standard (ISO 8601). Anyone who uses anything else is the kind of person who becomes a featured article here.

I don't need no commie govment agency to tell me how to format a string.

• Hmmmm (unregistered) in reply to PiisAWheeL
PiisAWheeL:
Hmmmm:
Crisw:
How does that handle time dilation at speeds approaching c?

I suspect the number of visitors to this site that can reason intelligently about relativity is less than or equal to the number of states that a boolean can have...

2. Tell me, How did you calculate that number?

You may as well ask how Silberstein calculated the value 3...

• (cs) in reply to Hmmmm
Hmmmm:
PiisAWheeL:
Hmmmm:
Crisw:
How does that handle time dilation at speeds approaching c?

I suspect the number of visitors to this site that can reason intelligently about relativity is less than or equal to the number of states that a boolean can have...

2. Tell me, How did you calculate that number?

You may as well ask how Silberstein calculated the value 3...

Not "how many states can boolean have". How did you figure there are only 2 people on this forum who can discuss reletivity? By what scientific process did you use to determine or what equation did you use? I'm trolling here and you aren't being very cooperative.

YYYY-MM-DD is the only one that sorts properly and that's why it's the standard (ISO 8601). Anyone who uses anything else is the kind of person who becomes a featured article here.
I don't need no commie govment agency to tell me how to format a string.
No, but you need a brain to tell you how to format a date, and if your brain arrived at anything other than YYYY-MM-DD, it needs to be replaced.
• Myth (unregistered) in reply to PiisAWheeL
PiisAWheeL:
Crisw:
Carl:
Now that we are on the verge of becoming a spacefaring civilization, it is long past time to discard our backwater planet-centric timekeeping system in favor of something Universal.

I propose a simple floating point counter of seconds since the big bang. Should work anywhere, forever. Leap second, leap year, Y2K, December 2012... who cares? Just keep incrementing that counter!

How does that handle time dilation at speeds approaching c?

It doesn't. You will need to do the math to adjust the rate at which your counter increments as you increase in speed.

But what do you use as the universal reference point? The Earth? The center of the Galaxy?

• (cs) in reply to Silverhill
Silverhill:
Rick:
On a related note... The length of a year is natural. The length of a month is almost natural. Why seven days for a week? Purely biblical? One of the few factors of 28?
The principal lunar phase changes (new-->first quarter, first quarter-->full, etc.) are very close to seven days long.
This is not quite my area of expertise, but isn't the first quarter somewhat arbitrary? Why not a fifth moon?
• (cs) in reply to Myth
Myth:
PiisAWheeL:
Crisw:
Carl:
Now that we are on the verge of becoming a spacefaring civilization, it is long past time to discard our backwater planet-centric timekeeping system in favor of something Universal.

I propose a simple floating point counter of seconds since the big bang. Should work anywhere, forever. Leap second, leap year, Y2K, December 2012... who cares? Just keep incrementing that counter!

How does that handle time dilation at speeds approaching c?

It doesn't. You will need to do the math to adjust the rate at which your counter increments as you increase in speed.

But what do you use as the universal reference point? The Earth? The center of the Galaxy?

Nothing. You are the one moving through space at a higher rate of speed. Your clock is the one that is going to be ticking at a different rate compared to everyone else. You detect the gravitational forces that are affecting your spacecraft in real time and factor that into the equation that is calculating how fast your clock should tick. It will adjust the rate of time measurement in real time so that YOUR clock is the same as everyone elses when you slow back down again.

• Hmmmm (unregistered) in reply to PiisAWheeL
PiisAWheeL:
Hmmmm:
PiisAWheeL:
Hmmmm:
I suspect the number of visitors to this site that can reason intelligently about relativity is less than or equal to the number of states that a boolean can have...
2. Tell me, How did you calculate that number?

You may as well ask how Silberstein calculated the value 3...

Not "how many states can boolean have". How did you figure there are only 2 people on this forum who can discuss reletivity? By what scientific process did you use to determine or what equation did you use? I'm trolling here and you aren't being very cooperative.

1. I thought my use of the phrase "I suspect" was sufficient indication that I hadn't "calculated" anything.

2. I was going to use the phrase "can be counted on the fingers of one foot" but I know I can reason intelligently about relativity so that ruled out that "joke". Also, I didn't want to make the assumption that I was the only one and the boolean states seemed to tie in nicely with the Silberstein/Eddington incident.

3. I'm very young and skinny and wouldn't be very nice to eat but my big brother will be along in a few minutes and he will taste much nicer...

• Hmmmm (unregistered) in reply to PiisAWheeL
PiisAWheeL:
Myth:
But what do you use as the universal reference point? The Earth? The center of the Galaxy?
Nothing. You are the one moving through space at a higher rate of speed. Your clock is the one that is going to be ticking at a different rate compared to everyone else. You detect the gravitational forces that are affecting your spacecraft in real time and factor that into the equation that is calculating how fast your clock should tick. It will adjust the rate of time measurement in real time so that YOUR clock is the same as everyone elses when you slow back down again.

Then again, comments such as these don't support my suspicion there are more than one...