"Bayley, Alistair"
- UTC/POSIX/CalenderTime are isomorphic, and represent some idealised notion of time where leap seconds don't exist i.e. a day always has duration 23:59:59.
I don't think this is correct. In UTC, extra leap seconds are denoted 23:59:60 and the missing ones have :59:58 as the last second. Posix's seconds are thus not isomorphic to UTC.
- Most (all?) system clocks return UTC. They may slow down around leap seconds to support this - is this behaviour only seen on systems with NTP?
I think so.
- It's not possible to simply get the number of actual ticks since some epoch; the OS time function may slow down for leap seconds and we can't avoid this.
Unless you move the epoch, which is basically what POSIX does. -kzm -- If I haven't seen further, it is by standing in the footprints of giants