RE: [squid-users] ACLs based on Time and LDAP groups

> In fact, NTP has no clue about what timezone the machine is in at
> all. All time is kept in seconds-from-epoch, timezone is something
> that is applied later. It certainly sounds like your timezone setting
> has been borked as Colin suggests.

This is OT here, but NTP does in fact have its own timescale, which is based
on UTC. From http://www.eecis.udel.edu/~mills/leap.html, we learn that the
UTC era began at 0h on 01 Jan 1972, while the NTP era began at 0h on 01 Jan
1900. There is a fixed difference between the NTP timescale and UTC. TAI, on
the other hand, is offset to both by the leap seconds inserted to keep UTC
in conformance with astronomical time. From a recent thread on the postfix
users mailing list, I gathered that POSIX defines the UNIX clock to read the
seconds (and microsecond fraction) since the bgeinning of the UNIX epoch,
which is, IIRC, 0h on 01 Jan 1970. That would be following TAI, not UTC.
However, there are localtime libraries that are aware of leap seconds and
adjust the time output accordingly.

There are 28 leap seconds right now, IIRC, with one being inserted roughly
every 15 months. Many people don't care about an offset of that size.

Just for your information.
Tobias Reckhard
Received on Thu Nov 28 2002 - 00:35:06 MST