Cron - First Saturday of the month

[Larry Wall]

In article <1489 at hagbard.dc.luth.se> bj at 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 at jpl-devvax.jpl.nasa.gov