[Python-Dev] datetime nanosecond support

Christian Heimes lists at cheimes.de
Thu Jul 26 15:00:52 CEST 2012

Am 25.07.2012 16:38, schrieb Guido van Rossum:
> Beware, people requesting dates BC rarely know what they are asking
> for. (E.g. Jesus wasn't born on 12/25/0001.) The calendrical
> ambiguities are such that representing dates that far in the past is
> better left to a specialized class. Read the original discussions
> about the datetime type; it loses meaning for dates long ago even if
> it can represent them, but the choice was made to ignore these and to
> offer a uniform abstraction for 1 <= year <= 9999. 

For starters. Calendars have more subtle edge cases, for example TAI has
a 10 second offset from UTC plus 15 leap seconds. Or the leap year
errors in Julian calendar that are handled differently in proleptic
Julian calendar which has unsystematic leap years between 45 BC and 4
AD. The rotation velocity of the Earth isn't constant, too. It's a major

> TBH I'm more worried about years >= 10000. :-)

Why life in the past? The future is ... err the future! :)


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