First proposal for new ISO C 9x time API
D. J. Bernstein
djb at cr.yp.to
Fri Sep 4 23:19:17 UTC 1998
I should make clear that the design of libtai is focused on the needs of
real programs. Here are the top two uses of timestamps in existing code:
* Subtraction. ``Tell me exactly how much time this took.''
* Conversion to civil time. ``The user wants to know when that was.''
Complete support for both of these functions is IMPOSSIBLE if you don't
have an up-to-date leap-second table. (Proof: If you _do_ have both of
those functions, you can easily print an up-to-date leap-second table.)
Markus Kuhn writes:
> My API does not require any leapsecond history to be stored
Then your API is fundamentally broken. How do you expect people to
compute accurate time differences?
> something which I would never expect to be updated reliably in practice.
In theory the necessary information is already transferred by NTP---
although a new protocol would be a good idea for obvious reasons.
Binary qmail distributions are allowed! http://pobox.com/~djb/qmail/dist.html
More information about the tz