Simon Marlow wrote: > John suggested using (pico)seconds since 1970-01-01 00:00:10 TAI. Isn't this equivalent to saying that ClockTime is the number of > seconds since 1970-01-01 00:00:00 UTC? Yes. TAI started ticking on 1 Jan 1958. UTC started ticking on 1 Jan 1972, and started 10 seconds behind of TAI (to keep it within 0.9 sec of UT1). -- Matthew Donadio (m.p.donadio@ieee.org)