[LEAPSECS] How good could civil timekeeping be?

[M. Warner Losh]

In message: <0802142245.AA26840 at ivan.Harhan.ORG>
            msokolov at ivan.Harhan.ORG (Michael Sokolov) writes:

: Poul-Henning Kamp <phk at phk.freebsd.dk> wrote:

: 

: > This is the point where the POSIX people shot us in the feet by

: > ignoring leap-seconds.

: 

: Why care about POSIX at all?  Why not use a non-POSIX UNIX system then?


Lots of code cares about many properties that POSIX has.


: > The time_t type, contains the number of SI seconds since 1970-01-01

: > 00:00:00 UTC *ignoring all leapseconds*.

: 

: Dunno about POSIX, but in UNIX-in-4-capitals which predates POSIX,

: time_t does NOT mean what you say.  UNIX as opposed to POSIX time_t

: measures the angle by which the hands of a wall clock have rotated since

: since they displayed midnight 1970-01-01 in Greenwich.  It is a wall

: clock rotation angle and has absolutely nothing to do with SI seconds or

: physical time interval.


You have just described POSIX time.


: > And down at a hairsbreadth, you cannot by looking at a time_t value,

: > tell the leap second from the second right before it.  (In some

: > cases it's the second after, but that's clearly a bug since the

: > leap second is the last second in the preceeding 24 hour UTC period.)

: 

: Rubber seconds solve this problem.


No they don't.  Rubber seconds are even more evil than leap seconds.

Warner