[Tfug] Today: time 1,234,567,890 seconds

[Angus Scott-Fleming]

On 13 Feb 2009 at 20:56, erich  wrote:

> Hmmm,
>            That works out to about 39.147 years. 1970 is when I got my
> degree, and UNIX was definitely around at that time. That's 75BCD15 in HEX,
> so I'm wondering if something significant about HW/SW architecture happened
> at that time. 

Apparently not, just blind luck and lots of quibbling at the standards bodies.  
The first Unix epoch actually started a year later but was adjusted back to 
1970 later for some reason that I haven't found.  At least that's what 
Wikipedia says, and I don't think Wikipedia would have any political bias for 
or against 1970 or 1971 ....

------- Included Stuff Follows -------
Unix time - Wikipedia, the free encyclopedia

    Unix time, or POSIX time, is a system for describing points in time, 
    defined as the number of seconds elapsed since midnight Coordinated 
    Universal Time (UTC) of January 1, 1970, not counting leap seconds.

    ... The earliest versions of Unix time had a 32-bit integer incrementing 
    at a rate of 60 Hz, which was the rate of the system clock on the hardware 
    of the early Unix systems. The value 60 Hz still appears in some software 
    interfaces as a result. The epoch also differed from the current value. 
    The first edition Unix Programmer's Manual dated November 3, 1971 defines 
    the Unix time as "the time since 00:00:00, Jan. 1, 1971, measured in 
    sixtieths of a second".  

    ...

    Vernor Vinge's novel A Deepness in the Sky describes a space-faring 
    trading civilization tens of thousands of years (hundreds of gigaseconds) 
    in the future that apparently still uses the Unix epoch, despite the 
    apparent problems that would have arisen with older Unix systems following 
    the Year 2038 Problem. It is noted that this epoch is approximately when 
    man first walked on the moon which is what the Qeng Ho mistakenly believe 
    is the basis for their calendar. However, the timekeeping code is layered 
    upon ancient programs including one that is implied to be based on the 
    Unix epoch.[2] [3]  

--------- Included Stuff Ends ---------
http://en.wikipedia.org/wiki/Unix_time

I think I have a copy of that Vinge novel, I'll have to dig it out and scour it 
for epoch references [g]

See also "History of IEEE P1003.1 POSIX time" -- search for "1970" on this 
page:
http://www.mail-archive.com/leapsecs@rom.usno.navy.mil/msg00109.html

When reading up on this, I was amused to see the origin of the abbreviation UTC 
(for Coordinated Universal Time).  Why did they choose UTC instead of CUT?  The 
French wouldn't accept CUT and the English wouldn't accept the French TUC. 
[BSEG]

------- Included Stuff Follows -------
NIST Time and Frequency FAQ

  Why is UTC used as the acronym for Coordinated Universal Time instead of CUT?
  http://tf.nist.gov/general/misc.htm#Anchor-14550

          In 1970 the Coordinated Universal Time system was devised by an 
    international advisory group of technical experts within the International 
    Telecommunication Union (ITU). The ITU felt it was best to designate a 
    single abbreviation for use in all languages in order to minimize 
    confusion. Since unanimous agreement could not be achieved on using either 
    the English word order, CUT, or the French word order, TUC, the acronym 
    UTC was chosen as a compromise.

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--
Angus Scott-Fleming
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