Lets see: minute hour day-of-the-month month day-of-the-week Code (markup): */4 */2 3,5 2,4 0 Code (markup): On February and April (2,4), on the 3rd and 5th days of the month (3,5). From 2 to 2 hours (*/2), every 4 minutes (*/4). Summarizing: on February the 3rd/5th and on April the 3rd/5th - when the hour is a multiple of 2 (0,2,4,6,8,10,12,14,16,18,20,22) the script will be run every 4 minutes. I think that's it.