Cron Midnight on 1st and Last Day of Month

Running a cron job on the "first and last day of the month" is tricky because months have different lengths (28-31 days). There's no direct "last day" syntax in standard cron. One approach is 0 0 1,28-31 * * combined with application logic to check if today is actually the last day.

A simpler method uses two cron entries: one for the first (0 0 1 * *) and a script for the last day that checks: [ "$(date -d tomorrow +%d)" = "01" ] && run_job. The Quartz scheduler supports L in the day-of-month field: 0 0 1,L * ? runs on the 1st and last day directly.

This pattern is common for month-opening and month-closing financial operations, beginning and end of month reporting, and billing cycle boundaries. The first day starts new month processing while the last day closes out the current month.