Not every Monday and additionally the 1st through 7th, as the
previous cron configuration actually meant. Turns out the command
runs when either the day of week matches _or_ the day of month
matches, unlike all the other rules.
# DO NOT EDIT - This file is being maintained by Chef
MAILTO=zerebubuth@gmail.com
# run this on the first monday of the month at 3:44am
-44 3 1-7 * mon www-data /usr/local/bin/old-planet-file-cleanup --dry-run --debug
+44 3 1-7 * * www-data test $(date +\%u) -eq 1 && /usr/local/bin/old-planet-file-cleanup --dry-run --debug