why- Open BSD .rocks

cron(8) (∞)

OpenBSDā€™s cron(8) daemon can randomize values (~), and prevent multiple jobs from running concurrently (-s). Super useful additions that all cron implementations should have had forever.

For example “0~30” will result in a random value between 0 and 30 inclusive. If either (or both) of the numbers on either side of the ‘~’ are omitted, the appropriate limit (low or high) for the field will be used.

Example:

0~30 1 * * * [-nsq] echo foo

These features are included in OpenBSD 6.7.

Details: