Execute cron on a specific day of the month

# Run on every second Tuesday of the month

20 4 8-14 * * test $(date +%u) -eq 2 && /usr/bin/bash /home/user/mytuesdayscript.sh

Explanation:

Run at 04:20 on every day-of-month from 8 through 14.

• 20   = 20th minute
• 4    = 4am
• 8-14 = between day 8 and day 14 (second week)
• *    = every month
• *    = every day of the week

But we are testing if day is number 2 (Tuesday. Sunday is 0) and we only run the script in this day.