Markus Kuhn wrote:
Note that there is no reason for the tagging to show up in the bits of the value. The tagging can be done implicitly by naming your variables in software such that they make clear whether they are intended for UTC or TAI or whatever values.
It is not *necessary* for the timestamp-type to appear in the timestamp, but doing so costs only a few bits and provides an excellent defensive programming mechanism: it prevents you from attempting to convert TAI timestamps to the local timezone, a meaningless activity.
Question: What precisely does "proleptic" mean and where is it defined. The most official definition of the Gregorian calendar that I have to reference is ISO 8601, and it does not use the term "proleptic". My time and astronomy references to not define the term either.
The WWWebster dictionary defines "prolepsis" as: anticipation: the representation or assumption of a future act or development as if presently existing or accomplished [...] "Proleptic" would be the standard adjectival form. The HP MPE/ix documentation (http://jazz.external.hp.com/src/year2000/dateintr.txt) says: # All the date intrinsics follow what is called the "Proleptic Calendar". # Stated in simple terms this calendar ignores the fact that calendars in # different countries changed at different times (around the year 1753) . # In other words, there are no lost days and there is no year 0. This is # similar to the calendar used by ALLBASE/SQL date/time functions. The Julian Day count is based on a "proleptic Julian calendar", i.e. the Julian calendar as if it was in use from 4713 B.C.E. to the present. -- John Cowan http://www.ccil.org/~cowan cowan@ccil.org You tollerday donsk? N. You tolkatiff scowegian? Nn. You spigotty anglease? Nnn. You phonio saxo? Nnnn. Clear all so! 'Tis a Jute.... (Finnegans Wake 16.5)