Re: [art] Predictable Internet Time

[Philip Homburg <[e-mail]>]

>I know of no POSIX system with a cesium atomic clock.
>
>The issue is that POSIX really runs off of whatever local source of time
>passage is available, and can (and does) drift from TAI on *each*
>system. That drift can't be determined until your system tries to sync
>with an external source (e.g., via NTP).

To be completely pedantic, a single cesium clock will also drift from TAI/UTC.

There is no such concept as being in sync with TAI without external
corrections.

To be even more pedantic, of course that depends on the desired accuracy.
A cesium clock could easily stay within one hour from TAI for a period of a 100
years. A random PC with a quarz crystal at room temperature would have a hard
time doing that.