Schedule cron from 10PM to 1AM every half an hour

Question

I am looking to schedule a cron from 10PM to 1AM(both inclusive) every half an hour .

I tried this */30 22-0 * * * doesn't seem to work after 11:30 PM or to be specific this works till 11:59 PM I guess.

This might help: https://unix.stackexchange.com/a/138842/74329 — Cyrus, Dec 20 '19 at 20:08
*/30 0,22-23 * * * will run 22:00 22:30 23:00 23:30 0:00 0:30 — EnlightMe, Dec 20 '19 at 20:10
You may shift it by 1 minute to get close to 1:00 (22:29 22:59 23:29 23:29 0:29 0:59) with 29/30 0,22,23 * * * — EnlightMe, Dec 20 '19 at 20:19

score 2 · Answer 1 · answered Dec 20 '19 at 20:24

Cron doesn't always provide the syntax to specify the times you want in a single line, but there's usually a workaround using two lines (or sometimes more).

Based on your description, apparently a range whose upper bound is smaller than its lower bound doesn't wrap around; rather it just seems to extend to the end of the day/hour/whatever. In your case, 22-0 apparently represents hours 22 and 23, and presumably 22-5, for example, would mean the same thing. (The man page is unclear on this.)

This should do the trick, though I haven't had a chance to test it:

*/30 22-23 * * * <command> # 22:00, 22:30, 23:00, 23:30
*/30 0     * * * <command> # 00:00, 00:30
0    1     * * * <command> # 01:00

Romeo Ninov · Answer 2 · 2019-12-21T07:32:07.400

2

Based on the other answer: You can make the crons one line less by combine records for 22-23 and 0 hour:

*/30 0,22-23 * * * <command>
0    1     * * * <command>

In some UNIX operating systems this may not work and you should explicitly mention the hours and minutes:

0,30 0,22,23 * * * <command>
0    1     * * * <command>

edited Dec 21 '19 at 07:32

answered Dec 21 '19 at 06:18

Romeo Ninov

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Schedule cron from 10PM to 1AM every half an hour

2 Answers2