Say I have a crontab which runs every 20
minutes and I have a hour range which can vary so lets say a-b
, which in one example could look like
GK27's answer does not fully answer the question, so let me clarify:
cron
will run jobs when the time matches the expression provided. Your expression tells it to run when the minute is divisible by 20 (*/20
) and your hour range tells it to run when the hour is within the specified range inclusively (5-23
). The remaining three *
tell it to match any day, month, and any day of the week.
Therefore the first job will run at 05:00 because the hour, 05
, is in the range 5 to 23 and the minute, 00
, is divisible by 20. The last job will run at 23:40 because the hour, 23
, is in the range 5 to 23 and the minute, 40
, is divisible by 20. It will not run at 00:00 because the hour, 00
, is not in the range 5 to 23.