Are you sure? The man page for Vixie cron at least doesn't imply that and it's not what I remember, and the web page this links to also doesn't think that's true. So "First Friday of the month at midnight" gives "0 0 1-7 * 5".
Note: The day of a command's execution can be specified by two fields — day of month, and day of week. If both fields are restricted (i.e., aren't ), the command will be run when either field matches the current time. For example, ``30 4 1,15 5'' would cause a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday.
Note: The day of a command's execution can be specified by two fields — day of month, and day of week. If both fields are restricted (i.e., aren't ), the command will be run when either field matches the current time. For example, ``30 4 1,15 5'' would cause a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday.