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From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.unix.wizards
Subject: Re: Cron - First Saturday of the month
Message-ID: <9155@jpl-devvax.JPL.NASA.GOV>
Date: 15 Aug 90 23:14:42 GMT
References: <1990Aug8.185745.16606@iwarp.intel.com> <1990Aug11.030818.28876@watserv1.waterloo.edu> <3706@aspect.UUCP> <1489@hagbard.dc.luth.se>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 17

In article <1489@hagbard.dc.luth.se> bj@dc.luth.se (B|rje Josefsson) writes:
: Slightly a side question according to the Subject:, but how to setup a
: command for execution on the LAST day of the month ONLY? 
: 
: I could use:
:             0 0 31 1 * command
:             0 0 28 2 * command
:             0 0 31 3 * command
:             and so on
: but that will not work on leap years...

I'd suggest (surprise, surprise)

    0 0 * * * perl -e '(localtime(time + 24*60*60))[3] == 1 && exec "command"'

or, more concisely

    0 0 * * * perl -e 'exit+(localtime time+86400)[3]-1' && command

Larry Wall
lwall@jpl-devvax.jpl.nasa.gov