0README

chgdate
|-- 0NOTE			obvious
|-- 0README			this file
|-- Makefile			makefile
|-- chgdate.1			man page
|-- chgdate.c			source file
|-- getdate.3			man page
|-- getdate.c			source file
|-- getlex.l			source file
|-- getmisc.c			source file
|-- getyacc.h			source file
|-- getyacc.y			source file
|-- jul_greg.c			source file
`-- jul_greg.h			source file


NAME
       chgdate - print result of date modification commands
SYNOPSIS
       chgdate [ -n ] [ date [ date_modifier_list ] ] |
       [ modified_date    -    modified_date ]
DESCRIPTION
       Chgdate  wraps the getdate(3) function for use by the shell.  It passes
       the command line to getdate(3), which parses the first word(s)  of  the
       command  string  to obtain a 'start date', and then applies an optional
       list of date modification instructions.  The result, in one of  several
       formats, is written to stdout.  Alternatively, if the command line con-
       tains the 'minus' ( - ) binary operator, the result is  the  number  of
       days  difference  between two dates.  No argument or the argument 'now'
       or 'today' returns today's date.  Chgdate can be used  to  interconvert
       Julian  and  Gregorian  dates,  because  either form of the date can be
       given as input, and both forms are included in the output.

       Syntax for a date is relatively loose:
            { now | today |  weekday  |  month  day[,  year]  |  mm/dd[/yy]  |
            {month|mm} number weekday | julian_day }

       A  date  modification sequence consists of two arguments: an optionally
       signed number and either a units specification or a weekday:
            { [+|-]number    { units | weekday } }
       The units specification is a one-letter or full-word identifier:
            { d[ay] | w[eek] | m[onth] | y[ear] }

       For the particular case of a number-weekday sequence, the date  can  be
       given  by a single preceding identifier or number, corresponding to the
       month.

       Command line options for the format of the output of getdate are
       specified by a leading "-n".

EXAMPLES
            $ chgdate now
            Apr 25, 1989 (Tue) 2447642
            $ chgdate now 1 y 1 m 1 w 1 d
            Jun 02, 1990 (Sat) 2448045
            $ chgdate now 1 y 1 m 1 w 1 d - now
            403
            $ chgdate -3 6 3 mon
            Jun  19   1989 Mon  2447697
            $ chgdate -2 1/1/70
            1    1    1970 4    2440588
AUTHOR
       j.a. rupley, tucson, az  85716


[see man pages chgdate.1 and getdate.3]



John Rupley
 rupley@u.arizona.edu -or- jar@rupley.com
 30 Calle Belleza, Tucson AZ 85716 - (520) 325-4533; fax - (520) 325-4991
 Dept. Biochemistry & Molecular Biophysics, Univ. Arizona, Tucson AZ 85721