Am Do., 13. Okt. 2022 um 17:31 Uhr schrieb John Cowan <[email protected]>: > > > > On Thu, Oct 13, 2022 at 2:40 AM Marc Nieper-Wißkirchen > <[email protected]> wrote: > >> What do you mean by "tai-epoch-time", by the way? > > > 1958-01-01T00:00:00 UTC (which is the point at which UTC-TAI is zero). > > By the way, it turns out that not all TAI seconds are the same length, per > WIkipedia: > > In the 1970s, it became clear that the clocks participating in TAI were > ticking at different rates due to gravitational time dilation, and the > combined TAI scale, therefore, corresponded to an average of the altitudes of > the various clocks. Starting from the Julian Date 2443144.5 (1 January 1977 > 00:00:00), corrections were applied to the output of all participating > clocks, so that TAI would correspond to proper time at the geoid (mean sea > level). Because the clocks were, on average, well above sea level, this meant > that TAI slowed by about one part in a trillion. > > However, I think we can ignore this discrepancy.
Or, we simply make Julian Date 2443144.5 the fixed epoch being returned by (epoch-time). From then on, proper time (of the reference frame of Earth's geoid) and TAI time correspond. >> Would it make sense to define a jiffy as a nanosecond for >> implementations of the large language? > > > That works for me. https://codeberg.org/scheme/r7rs/issues/97 PS: What kind of second does SRFI 19's time difference store by the way?
