[LEAPSECS] A new use for Pre-1972 UTC

Poul-Henning Kamp phk at phk.freebsd.dk
Tue Feb 17 15:53:43 EST 2009

In message <B0E6460C-808B-4EB4-ADB7-6FA0BB5A1765 at noao.edu>, Rob Seaman writes:

>What exactly

>is the use case they are trying to satisfy? That said, I'm with

>Tony. This seems like what ISO 8601 was designed for.

They are trying to make a unique pseudo-random number, not a timestamp.

To decrease the probability of two persons or programs choosing the
same number, then include a timestamp in it.

time_t values are readily available in all POSIX filesystems,
so they use that.

This is a variant of the UUID madness that somebody came up with
because they didn't want to run a registry or use the existing
well-structured process (ISO OID's) and though that the eventual
collisions "probably doesn't matter much".


Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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