date_rest.tex

CCSM Research Tools: Community Atmosphere Model (CAM)

% $Id: Date_rest.tex,v 1.1.6.1 2002/04/24 03:25:48 erik Exp $

The Gregorian date object is limited to the range
November 25, -4713 to December 31, +214748 (both in the Gregorian calendar).  The lower limit
is due to the algorithm used in the Gregorian calendar, which relies on
calculating the julian day.  This calculation is valid only for a positive
julian day, and the lower limit corresponds to the julian day of one.  The
upper limit is imposed because January 1, 214749 is expressed in the {\tt yearmmdd}
format as 2147490101, which is larger than \( 2^{31} \).

The No Leap date object is limited to the range January 1, -214748 to
December 31, +21478 .  Both of these limitations derive from the {\tt yearmmdd}
interface and the fact that the year 21479 (B.C. or A.D.) can not be represented
in this format and a 4-byte integer.