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Calendar/

julday.pro

Calculate the Julian Day Number for a given month, day, and year. This is the inverse of the library function caldat. 3 calendars are available according to the value of key_caltype (variable of the common file cm_4cal): 'greg', '360d', 'noleap'

topjulday Calendar

result = julday([month][, day][, yearin][, hour][, minute][, second], NDAYSPM=integer)

Return value

the Julian Day Number (which begins at noon) of the specified calendar date. If Hour, Minute, and Second are not specified, then the result will be a long integer, otherwise the result is a double precision floating point number.

Parameters

month        in optional type: scalar (integer or double) or array of scalars

Number of the desired month (1 = January, ..., 12 = December).

day        in optional type: scalar (integer or double) or array of scalars

Number of day of the month.

yearin        in optional type: scalar (integer or double) or array of scalars

Number of the desired year.Year parameters must be valid values from the civil calendar. Years B.C.E. are represented as negative integers. Years in the common era are represented as positive integers. In particular, note that there is no year 0 in the civil calendar. 1 B.C.E. (-1) is followed by 1 C.E. (1). Change: However for climatological year, we do accept the year 0 but we change it for year 654321L (the same trick is done in caldat so caldat, julday(1,1,0) gives you back Jan 1st of year 0)

hour        in optional type: scalar (integer or double) or array of scalars default: 12

Number of the hour of the day.

minute        in optional type: scalar (integer or double) or array of scalars default: 0

Number of the minute of the hour.

second        in optional type: scalar (integer or double) or array of scalars default: 0

Number of the second of the minute.

Keywords

NDAYSPM        type: integer default: 30

To use a calendar with fixed number of days per month. see also the use of key_caltype (variable of the common file cm_4cal)

Version history

Version

$Id: julday.pro 396 2009-04-08 16:14:31Z smasson $

History

Translated from "Numerical Recipes in C", by William H. Press, Brian P. Flannery, Saul A. Teukolsky, and William T. Vetterling. Cambridge University Press, 1988 (second printing). AB, September, 1988 DMS, April, 1995, Added time of day. Eric Guilyardi, June 1999 Added key_work ndayspm for fixed number of days per months CT, April 2000, Now accepts vectors or scalars. Sebastien Masson, Aug. 2003 fix bug for negative and large values of month values eg. julday(349,1,1970) Sebastien Masson, May 2006, add different calendat with key_caltype (variable of the common file cm_4cal)

Known issues

Restrictions

The result will have the same dimensions as the smallest array, or will be a scalar if all arguments are scalars. Accuracy using IEEE double precision numbers is approximately 1/10000th of a second, with higher accuracy for smaller (earlier) Julian dates.

Other attributes

Uses routines

cm_4cal

Statistics

McCabe cyclic 43
McCabe essential 1
McCabe modular design 1
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