Revision of ISO C 9x <time.h>

Joseph S. Myers jsm28 at
Thu Sep 3 20:06:37 UTC 1998

On Thu, 3 Sep 1998, Markus Kuhn wrote (quoting Clive Feather):

> (9) All new functions to be re-entrant.

As noted before on this list: this means that timezones should be explicit
parameters, and new functions should not have implicit dependence on the
local timezone, though they may have such dependence on the locale.
However the re-entrant functions from POSIX should maybe still be included
despite not having explicit timezone parameters (ctime_r, localtime_r).

> Anything else ?

Some more points that need to be covered:

*) Allowing conforming implementations both with and without leapsecond

*) Retaining compatibility with systems on which time_t does not allow for
leapseconds, as well as those on which it does, while still allowing those
on which it doesn't allow for leapseconds (e.g. POSIX) to have leapsecond
support and TAI<->UTC conversions through new interfaces.

*) Allowing for real timezones (presumably through compiling timezone
descriptions from a TZ string which could represent a POSIX timezone or an
implementation extension beginning with ':').

Joseph S. Myers
jsm28 at

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