1 BCE versus 0 CE

Markus Kuhn Markus.Kuhn at cl.cam.ac.uk
Fri Mar 4 11:54:15 UTC 2005

Ken Pizzini <tz. at explicate.org> wrote on 2005-03-04 00:13 UTC:
> >     - It appears unnecessary to control skipping the year zero.  I have
> >       not encountered any locale where there is such a beast; in all cases,
> >       it appears that the year 1 B.C.E. is followed by the year 1 C.E.
> Astronomers, IIRC, use a calendar with a year zero -- it removes
> a gratuitous anomaly from calculations.  Regardless, for calendars
> where there is a BCE-CE type distinction, there is no year zero; in
> calendars where there is a year zero (e.g., "proleptic Gregorian"),
> the years preceeding year zero continue algebraically, starting
> with year -1.
>        (modern)  (classic)
>       Gregorian  Gregorian  Astro.
>      2005 CE     AD 2005     2005
>         2 CE        AD 2        2
>         1 CE        AD 1        1
>         1 BCE       1 BC        0
>         2 BCE       2 BC       -1
>      4004 BCE    4004 BC    -4003

The missing-year-0 BC(E) convention, as well as the 1-to-12-am-pm
notation, are wonderful examples for obsolete, inelegant and dangerously
fault-prone conventions. Responsible computer folks should stand up
against these and tell the world clearly and with force that in no way
can these ever be the recommended, proper, responsible ways of doing things.

Do not fear the zero! There is a year 0 CE and a year -1 CE, just like
there is a time 00:00. Any older notational work-around should have been
abandoned after the zero became popular in Europe sometimes in the


Markus Kuhn, Computer Lab, Univ of Cambridge, GB
http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

More information about the tz mailing list