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February 13th, UNIX Time Will Reach 1234567890
Posted by
timothy
on Sun Feb 08, 2009 04:26 PM
from the less-often-than-a-stopped-clock-is-right dept.
from the less-often-than-a-stopped-clock-is-right dept.
mikesd81 writes "Over at Linux Magazine Online, Jon maddog Hall writes that on Friday the 13th, 2009 at 11:31:30pm UTC UNIX time will reach 1,234,567,890. This will be Friday, February 13th at 1831 and 30 seconds EST. Matias Palomec has a perl script you an use to see what time that will be for you:
perl -e 'print scalar localtime(1234567890),"\n";' Now, while this is not the UNIX epoch, Alan Cox does assure us that Linux is now working on 64-bit time, and the UNIX epoch 'roll-over' would happen about the time that the sun burnt out."
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Leap Seconds? (Score:5, Funny)
Is that with or without leap seconds?
Re:Leap Seconds? (Score:5, Funny)
On Friday the 13th, every second is a leap second. BOO!
Parent
Re: (Score:3, Insightful)
But here it won't happen until Saturday.
"Sat Feb 14 00:31:30 2009 CET"
With (Score:4, Informative)
Good question:
http://en.wikipedia.org/wiki/Unix_time [wikipedia.org]
the times it represents are UTC but it has no way of representing UTC leap seconds (e.g. 1998-12-31 23:59:60).
I don't think there's any defined way for a POSIX machine to deal with leap seconds. The usual solution is to slew the clock a bit after they occur.
Parent
Leap seconds (Score:5, Insightful)
Raw unix time is simply a count of seconds since a defined point in time - and has nothing to do with leap seconds. Leap seconds only come into play when converting to human readable display format (along with timezones and DST). Leap seconds have been handled for some time by the zoneinfo library used by most unix and linux distros. Even Java handles leap seconds with my port of zoneinfo to a Java TimeZone implementation [nyud.net].
The tzdata package included in most Linux distros includes leapsecond data in the "right" directory. You can find out the time including leapseconds by setting your TZ environment variable to "right/...". For instance:
$ TZ="right/US/Eastern" date; TZ="US/Eastern" date
Sun Feb 8 17:52:42 EST 2009
Sun Feb 8 17:53:06 EST 2009
Parent
Re: (Score:3, Informative)
Sorry, UNIX time is exactly 86400 seconds per day.
If you read this history of POSIX time [mail-archive.com] it becomes apparent that POSIX time is a mashup of UTC and GMT that is different to either.
The standard does not require your system clock to be accurate. When a leap second occurs, unless your POSIX system makes the effort to adjust its clock (say via the adjtimex(2) call), your POSIX system's clock will ignore the leap second.
To make matters worse, people are now syncing their systems to a UTC or TIA time source, or
Re:Leap seconds (Score:4, Informative)
Sorry, UNIX time is exactly 86400 seconds per day.
Exactly. Mod parent up. Mod gparent down.
date -u -d @1230767999
Wed Dec 31 23:59:59 UTC 2008
date -u -d @1230768000
Thu Jan 1 00:00:00 UTC 2009
What happened to the leap second? It was completely ignored, yep.
Parent
Re: (Score:3, Informative)
TZ="right/GB" date -d @1230768022
Wed Dec 31 23:59:59 GMT 2008
TZ="right/GB" date -d @1230768023
Wed Dec 31 23:59:60 GMT 2008
TZ="right/GB" date -d @1230768024
Thu Jan 1 00:00:00 GMT 2009
Re:Leap seconds (Score:4, Informative)
Total moderation failure...
Here's how the standard defines the meaning of "seconds since the epoch" in relation to UTC dates: http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap04.html#tag_04_14 [opengroup.org]
As you can see, the meaning is actually "seconds since the epoch, excluding leap seconds." Always read the definitions.
According to that definition, the time_t value of "Friday the 13th, 2009 at 11:31:30pm UTC" is:
30 + 31*60 + 23*3600 + 43*86400 + (109-70)*31536000 + ((109-69)/4)*86400 - ((109-1)/100)*86400 + ((109+299)/400)*86400
= 30 + 1860 + 39600 + 3715200 + 1229904000 + 864000 - 86400 + 86400
= 1234567890
So, to answer the question which started this: Not including leap seconds.
Besides, it should be "Friday the 13th, 2009 at 23:31:30 UTC." The am/pm notation is not without ambiguities.
Parent
Re: (Score:3, Informative)
Oh, that's right, it doesn't.
Exactly. That's why all programs should store and communicate future date/times in local time format (with the local timezone) and use GMT only for the current time or past events, because nobody knows when the government is going to come along and redefine time. Your 3PM appointment at the dentist is at 3PM regardless of how many leap seconds get inserted or if its decided that this year, daylight saving time will only shift by 30 minutes, or whatever other crisis may come.
Re: (Score:3, Insightful)
Linux interpretation of Posix (Score:5, Informative)
I am gratified to see that time() in gnu/linux returns seconds since the epoch. They mention the contradictory requirements of Posix, but opine that it was a technical error, and seconds since the epoch is what they really meant (or should have meant).
NOTES POSIX.1 defines seconds since the Epoch as a value to be interpreted as
the number of seconds between a specified time and the Epoch, according
to a formula for conversion from UTC equivalent to conversion on the
naive basis that leap seconds are ignored and all years divisible by 4
are leap years. This value is not the same as the actual number of
seconds between the time and the Epoch, because of leap seconds and
because clocks are not required to be synchronised to a standard refer-
ence. The intention is that the interpretation of seconds since the
Epoch values be consistent; see POSIX.1 Annex B 2.2.2 for further
rationale.
Parent
Re:With (Score:5, Informative)
Unix clock is using the metric system. "Second", after all, is the metric unit for time, and Unix clock simply counts the seconds after a certain point in time. It's only the human representation of that value which deals with minutes and such.
Parent
Re:With (Score:5, Informative)
in what way is the "second" metric?
How about this way? [nist.gov]
Parent
Re: (Score:3, Informative)
The second is the official SI unit of time.
http://en.wikipedia.org/wiki/SI [wikipedia.org]
Re: (Score:3, Insightful)
See here [wikipedia.org].
I'd like the metric system to take over our measurement of time, but, disregarding other problems, it won't solve the leap second issue all by itself.
Re:With (Score:5, Informative)
The french tried it. It failed.
The days(fixed) in a year(fixed) are not divisible by 10 so there were days without a month. Furthermore it increases the number of days in each week and it changed the definition of the hour(10 each day) the minute(100 each hour) and the second(100 each minute).
All in all, it was a mess. Not designed with nature as a guideline(like pretty much all other calendars) but with the number 10, a number based on the fingers on our hands.
http://en.wikipedia.org/wiki/French_Republican_Calendar [wikipedia.org]
Parent
Re:With (Score:5, Funny)
The french tried it. It failed.
If any post should be marked redundant...
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Re:Leap Seconds? (Score:5, Funny)
What do you mean? An African or European leap second?
Parent
scalar() unnecessary (Score:5, Informative)
perl -e 'print localtime(1234567890) ."\n";'
Let the "." concatenate operator do it for you.
Re:scalar() unnecessary (Score:5, Interesting)
Fri Feb 13 13:45:21 2009
Apparently a palindrome is one the same day!
Parent
Re:scalar() unnecessary (Score:5, Informative)
Perl is unnecessary:
date -d@1234567890
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Re:scalar() unnecessary (Score:5, Funny)
Thus proving TMTOWTDI. ;)
Teenage mutant turtle on wild turtle date...? What the hell does I stand for?!
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why command-line? (Score:5, Interesting)
Parent
Re: (Score:3, Funny)
You are talking about the countdown to a "cool" number in UNIX time, and you don't want to use the command line???
It's also a notable day because... (Score:5, Funny)
Re:It's also a notable day because... (Score:5, Funny)
Then they look at you like you are an idiot and never talk to you again. enjoy you birthday alone.
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Re:It's also a notable day because... (Score:5, Funny)
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Re:It's also a notable day because... (Score:5, Funny)
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Re:It's also a notable day because... (Score:4, Funny)
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Actually, the date... (Score:4, Funny)
...that I really feel I missed:
$ perl -e 'print scalar localtime(8675309),"\n";'
Sat Apr 11 11:48:29 1970
What kind of stupid time is that? (Score:5, Funny)
So the time is 123456789? That's the stupidest time I've ever heard in my life... It sounds like something an idiot would have on his luggage.
Re: (Score:2, Funny)
Hey! That's my luggage combination!
Re: (Score:2)
That's amazing! I've got the same combination on my luggage!
And change the combination on my luggage!
Re: (Score:3, Insightful)
So the time is 123456789? That's the stupidest time I've ever heard in my life... It sounds like something an idiot would have on his luggage.
Indeed, it would be hard to find a more stupid era than Nov 1973. It was the height of the Watergate scandal, a time of inflation, energy crisis, bad haircuts, ugly suits, and the quality of pop music spiraling downward. Truly a nadir in modern history.
Re: (Score:3, Funny)
> and the quality of pop music spiraling downward. Truly a nadir in modern history.
I'd call that an inflection point. The nadir is TODAY.
Perl script is unnecessary (Score:5, Informative)
The standard unix date command will suffice:
date -d @1234567890
Re:Perl script is unnecessary (Score:5, Funny)
I've wasted my life.
Parent
For about half the world .... (Score:4, Interesting)
Y2^40K (Score:5, Funny)
Alan Cox does assure us that Linux is now working on 64-bit time, and the UNIX epoch 'roll-over' would happen about the time that the sun burnt out."
This is just the sort of short-sighted thinking that lead to our recent Y2K hysteria, except this time our poor beleaguered descendents will be in the middle of an exodus from the solar system when all their legacy systems throw simultaneous exceptions. This will of course cause their engine and guidance systems to fail, so that the last dying gasps of humanity will consist of:
dammit! (Score:4, Funny)
it's my password... now everyone know it, thanks SLASHDOT! :-)
Why all the hatin'? (Score:5, Insightful)
Yes, it's a slow news day and that's why this is on the front page! It's Sunday afternoon (for most of us), ferchrissakes.
So just enjoy it, it's geeky and novel. I don't think anybody meant for it to be considered a big deal, and if you don't find any fleeting moment of joy from it, just move along.
S^64 and Solar burnout (Score:5, Funny)
Alan Cox does assure us that Linux is now working on 64-bit time, and the UNIX epoch 'roll-over' would happen about the time that the sun burnt out."
So great, we're going to be dealing with the 64bit time roll over in the dark? What kinda planning is that! Do we have candles?
64-bit time EXCEPT... (Score:5, Interesting)
... for any application that assumes sizeof(time_t) is 32 bits.
Not that I'd expect that to be the case with any half-decent intelligently written application. But we all know how common applications which are neither half-decent nor intelligently written are...
Re:so what? (Score:5, Funny)
Wow, you must have a hard time finding joy in anything.
Parent
Re: (Score:3, Interesting)
11.23 seconds later UNIX time will reach 10^11/3^4. You can celebrate that instead.
Re:so what? (Score:4, Funny)
1234567890 is some arbitrary decimal string, if you wished to note a notable number, why not one which is 2^N, for something so entirely based within computers, it seems much more sensible to think in binary than some decimal number which happens to look a little pretty
Why do we have gaydar but not virgindar?
Parent
Re:so what? (Score:5, Funny)
However, considering that OSX is based on BSD, you can also get Apple pi.
Parent
Re: (Score:3, Informative)
I'm going to quit work before 2147483647 because I don't want to update all my code.
Re:Must be a slow news day.. (Score:5, Funny)
Or any OS, for that matter.
And now a bit of topical humor so this post isn't purely an exercise in pointing out the obvious: "Every day is a long day, because 86400 seconds won't fit in a short."
Parent