breakitdown / Cron / 0 0-21/3 * * * Every 90 minutes in cron
Answer One cron line cannot run every 90 minutes, because minute and hour fields repeat independently. Two lines can: 0 0-21/3 * * * (00:00, 03:00 … 21:00) and 30 1-22/3 * * * (01:30, 04:30 … 22:30) together give a run every 90 minutes.
0Minute 0-21/3Hour *Day of month *Month *Day of week
At minute 0 past 00:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00 and 21:00.
0Minute (0-59) At minute 0 (on the hour)
0-21/3Hour (0-23) Every 3rd hour from 00:00 through 21:00: 00:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00 and 21:00
*Day of month (1-31) Every day (no restriction)
*Month (1-12 or JAN-DEC) Every month
*Day of week (0-7 or SUN-SAT (0 and 7 = Sunday)) Every day (no restriction)
Next 10 runs in UTC 1 21:00 Sat, 31 Oct 2026in 43 minutes 2 00:00 Sun, 1 Nov 2026in 3 hours 3 03:00 Sun, 1 Nov 2026in 6 hours 4 06:00 Sun, 1 Nov 2026in 9 hours 5 09:00 Sun, 1 Nov 2026in 12 hours 6 12:00 Sun, 1 Nov 2026in 15 hours 7 15:00 Sun, 1 Nov 2026in 18 hours 8 18:00 Sun, 1 Nov 2026in 21 hours 9 21:00 Sun, 1 Nov 2026in 1 day 10 00:00 Mon, 2 Nov 2026in 1 day When it fires 8 runs a day on average56 a week364 of the next 364 days have a run
Hours of the week (darker = more runs) 00 03 06 09 12 15 18 21 Mon Mon 00:00-00:59: 52 runs over the next 364 days Mon 01:00-01:59: 0 runs over the next 364 days Mon 02:00-02:59: 0 runs over the next 364 days Mon 03:00-03:59: 52 runs over the next 364 days Mon 04:00-04:59: 0 runs over the next 364 days Mon 05:00-05:59: 0 runs over the next 364 days Mon 06:00-06:59: 52 runs over the next 364 days Mon 07:00-07:59: 0 runs over the next 364 days Mon 08:00-08:59: 0 runs over the next 364 days Mon 09:00-09:59: 52 runs over the next 364 days Mon 10:00-10:59: 0 runs over the next 364 days Mon 11:00-11:59: 0 runs over the next 364 days Mon 12:00-12:59: 52 runs over the next 364 days Mon 13:00-13:59: 0 runs over the next 364 days Mon 14:00-14:59: 0 runs over the next 364 days Mon 15:00-15:59: 52 runs over the next 364 days Mon 16:00-16:59: 0 runs over the next 364 days Mon 17:00-17:59: 0 runs over the next 364 days Mon 18:00-18:59: 52 runs over the next 364 days Mon 19:00-19:59: 0 runs over the next 364 days Mon 20:00-20:59: 0 runs over the next 364 days Mon 21:00-21:59: 52 runs over the next 364 days Mon 22:00-22:59: 0 runs over the next 364 days Mon 23:00-23:59: 0 runs over the next 364 days Tue Tue 00:00-00:59: 52 runs over the next 364 days Tue 01:00-01:59: 0 runs over the next 364 days Tue 02:00-02:59: 0 runs over the next 364 days Tue 03:00-03:59: 52 runs over the next 364 days Tue 04:00-04:59: 0 runs over the next 364 days Tue 05:00-05:59: 0 runs over the next 364 days Tue 06:00-06:59: 52 runs over the next 364 days Tue 07:00-07:59: 0 runs over the next 364 days Tue 08:00-08:59: 0 runs over the next 364 days Tue 09:00-09:59: 52 runs over the next 364 days Tue 10:00-10:59: 0 runs over the next 364 days Tue 11:00-11:59: 0 runs over the next 364 days Tue 12:00-12:59: 52 runs over the next 364 days Tue 13:00-13:59: 0 runs over the next 364 days Tue 14:00-14:59: 0 runs over the next 364 days Tue 15:00-15:59: 52 runs over the next 364 days Tue 16:00-16:59: 0 runs over the next 364 days Tue 17:00-17:59: 0 runs over the next 364 days Tue 18:00-18:59: 52 runs over the next 364 days Tue 19:00-19:59: 0 runs over the next 364 days Tue 20:00-20:59: 0 runs over the next 364 days Tue 21:00-21:59: 52 runs over the next 364 days Tue 22:00-22:59: 0 runs over the next 364 days Tue 23:00-23:59: 0 runs over the next 364 days Wed Wed 00:00-00:59: 52 runs over the next 364 days Wed 01:00-01:59: 0 runs over the next 364 days Wed 02:00-02:59: 0 runs over the next 364 days Wed 03:00-03:59: 52 runs over the next 364 days Wed 04:00-04:59: 0 runs over the next 364 days Wed 05:00-05:59: 0 runs over the next 364 days Wed 06:00-06:59: 52 runs over the next 364 days Wed 07:00-07:59: 0 runs over the next 364 days Wed 08:00-08:59: 0 runs over the next 364 days Wed 09:00-09:59: 52 runs over the next 364 days Wed 10:00-10:59: 0 runs over the next 364 days Wed 11:00-11:59: 0 runs over the next 364 days Wed 12:00-12:59: 52 runs over the next 364 days Wed 13:00-13:59: 0 runs over the next 364 days Wed 14:00-14:59: 0 runs over the next 364 days Wed 15:00-15:59: 52 runs over the next 364 days Wed 16:00-16:59: 0 runs over the next 364 days Wed 17:00-17:59: 0 runs over the next 364 days Wed 18:00-18:59: 52 runs over the next 364 days Wed 19:00-19:59: 0 runs over the next 364 days Wed 20:00-20:59: 0 runs over the next 364 days Wed 21:00-21:59: 52 runs over the next 364 days Wed 22:00-22:59: 0 runs over the next 364 days Wed 23:00-23:59: 0 runs over the next 364 days Thu Thu 00:00-00:59: 52 runs over the next 364 days Thu 01:00-01:59: 0 runs over the next 364 days Thu 02:00-02:59: 0 runs over the next 364 days Thu 03:00-03:59: 52 runs over the next 364 days Thu 04:00-04:59: 0 runs over the next 364 days Thu 05:00-05:59: 0 runs over the next 364 days Thu 06:00-06:59: 52 runs over the next 364 days Thu 07:00-07:59: 0 runs over the next 364 days Thu 08:00-08:59: 0 runs over the next 364 days Thu 09:00-09:59: 52 runs over the next 364 days Thu 10:00-10:59: 0 runs over the next 364 days Thu 11:00-11:59: 0 runs over the next 364 days Thu 12:00-12:59: 52 runs over the next 364 days Thu 13:00-13:59: 0 runs over the next 364 days Thu 14:00-14:59: 0 runs over the next 364 days Thu 15:00-15:59: 52 runs over the next 364 days Thu 16:00-16:59: 0 runs over the next 364 days Thu 17:00-17:59: 0 runs over the next 364 days Thu 18:00-18:59: 52 runs over the next 364 days Thu 19:00-19:59: 0 runs over the next 364 days Thu 20:00-20:59: 0 runs over the next 364 days Thu 21:00-21:59: 52 runs over the next 364 days Thu 22:00-22:59: 0 runs over the next 364 days Thu 23:00-23:59: 0 runs over the next 364 days Fri Fri 00:00-00:59: 52 runs over the next 364 days Fri 01:00-01:59: 0 runs over the next 364 days Fri 02:00-02:59: 0 runs over the next 364 days Fri 03:00-03:59: 52 runs over the next 364 days Fri 04:00-04:59: 0 runs over the next 364 days Fri 05:00-05:59: 0 runs over the next 364 days Fri 06:00-06:59: 52 runs over the next 364 days Fri 07:00-07:59: 0 runs over the next 364 days Fri 08:00-08:59: 0 runs over the next 364 days Fri 09:00-09:59: 52 runs over the next 364 days Fri 10:00-10:59: 0 runs over the next 364 days Fri 11:00-11:59: 0 runs over the next 364 days Fri 12:00-12:59: 52 runs over the next 364 days Fri 13:00-13:59: 0 runs over the next 364 days Fri 14:00-14:59: 0 runs over the next 364 days Fri 15:00-15:59: 52 runs over the next 364 days Fri 16:00-16:59: 0 runs over the next 364 days Fri 17:00-17:59: 0 runs over the next 364 days Fri 18:00-18:59: 52 runs over the next 364 days Fri 19:00-19:59: 0 runs over the next 364 days Fri 20:00-20:59: 0 runs over the next 364 days Fri 21:00-21:59: 52 runs over the next 364 days Fri 22:00-22:59: 0 runs over the next 364 days Fri 23:00-23:59: 0 runs over the next 364 days Sat Sat 00:00-00:59: 52 runs over the next 364 days Sat 01:00-01:59: 0 runs over the next 364 days Sat 02:00-02:59: 0 runs over the next 364 days Sat 03:00-03:59: 52 runs over the next 364 days Sat 04:00-04:59: 0 runs over the next 364 days Sat 05:00-05:59: 0 runs over the next 364 days Sat 06:00-06:59: 52 runs over the next 364 days Sat 07:00-07:59: 0 runs over the next 364 days Sat 08:00-08:59: 0 runs over the next 364 days Sat 09:00-09:59: 52 runs over the next 364 days Sat 10:00-10:59: 0 runs over the next 364 days Sat 11:00-11:59: 0 runs over the next 364 days Sat 12:00-12:59: 52 runs over the next 364 days Sat 13:00-13:59: 0 runs over the next 364 days Sat 14:00-14:59: 0 runs over the next 364 days Sat 15:00-15:59: 52 runs over the next 364 days Sat 16:00-16:59: 0 runs over the next 364 days Sat 17:00-17:59: 0 runs over the next 364 days Sat 18:00-18:59: 52 runs over the next 364 days Sat 19:00-19:59: 0 runs over the next 364 days Sat 20:00-20:59: 0 runs over the next 364 days Sat 21:00-21:59: 52 runs over the next 364 days Sat 22:00-22:59: 0 runs over the next 364 days Sat 23:00-23:59: 0 runs over the next 364 days Sun Sun 00:00-00:59: 52 runs over the next 364 days Sun 01:00-01:59: 0 runs over the next 364 days Sun 02:00-02:59: 0 runs over the next 364 days Sun 03:00-03:59: 52 runs over the next 364 days Sun 04:00-04:59: 0 runs over the next 364 days Sun 05:00-05:59: 0 runs over the next 364 days Sun 06:00-06:59: 52 runs over the next 364 days Sun 07:00-07:59: 0 runs over the next 364 days Sun 08:00-08:59: 0 runs over the next 364 days Sun 09:00-09:59: 52 runs over the next 364 days Sun 10:00-10:59: 0 runs over the next 364 days Sun 11:00-11:59: 0 runs over the next 364 days Sun 12:00-12:59: 52 runs over the next 364 days Sun 13:00-13:59: 0 runs over the next 364 days Sun 14:00-14:59: 0 runs over the next 364 days Sun 15:00-15:59: 52 runs over the next 364 days Sun 16:00-16:59: 0 runs over the next 364 days Sun 17:00-17:59: 0 runs over the next 364 days Sun 18:00-18:59: 52 runs over the next 364 days Sun 19:00-19:59: 0 runs over the next 364 days Sun 20:00-20:59: 0 runs over the next 364 days Sun 21:00-21:59: 52 runs over the next 364 days Sun 22:00-22:59: 0 runs over the next 364 days Sun 23:00-23:59: 0 runs over the next 364 days
The next 52 weeks, one square per day Mon Wed Fri Oct Sat 31 Oct 2026: 8 runs Sun 1 Nov 2026: 8 runs Mon 2 Nov 2026: 8 runs Tue 3 Nov 2026: 8 runs Wed 4 Nov 2026: 8 runs Thu 5 Nov 2026: 8 runs Fri 6 Nov 2026: 8 runs Sat 7 Nov 2026: 8 runs Sun 8 Nov 2026: 8 runs Mon 9 Nov 2026: 8 runs Tue 10 Nov 2026: 8 runs Wed 11 Nov 2026: 8 runs Thu 12 Nov 2026: 8 runs Fri 13 Nov 2026: 8 runs Sat 14 Nov 2026: 8 runs Sun 15 Nov 2026: 8 runs Mon 16 Nov 2026: 8 runs Tue 17 Nov 2026: 8 runs Wed 18 Nov 2026: 8 runs Thu 19 Nov 2026: 8 runs Fri 20 Nov 2026: 8 runs Sat 21 Nov 2026: 8 runs Sun 22 Nov 2026: 8 runs Mon 23 Nov 2026: 8 runs Tue 24 Nov 2026: 8 runs Wed 25 Nov 2026: 8 runs Thu 26 Nov 2026: 8 runs Fri 27 Nov 2026: 8 runs Sat 28 Nov 2026: 8 runs Sun 29 Nov 2026: 8 runs Mon 30 Nov 2026: 8 runs Dec Tue 1 Dec 2026: 8 runs Wed 2 Dec 2026: 8 runs Thu 3 Dec 2026: 8 runs Fri 4 Dec 2026: 8 runs Sat 5 Dec 2026: 8 runs Sun 6 Dec 2026: 8 runs Mon 7 Dec 2026: 8 runs Tue 8 Dec 2026: 8 runs Wed 9 Dec 2026: 8 runs Thu 10 Dec 2026: 8 runs Fri 11 Dec 2026: 8 runs Sat 12 Dec 2026: 8 runs Sun 13 Dec 2026: 8 runs Mon 14 Dec 2026: 8 runs Tue 15 Dec 2026: 8 runs Wed 16 Dec 2026: 8 runs Thu 17 Dec 2026: 8 runs Fri 18 Dec 2026: 8 runs Sat 19 Dec 2026: 8 runs Sun 20 Dec 2026: 8 runs Mon 21 Dec 2026: 8 runs Tue 22 Dec 2026: 8 runs Wed 23 Dec 2026: 8 runs Thu 24 Dec 2026: 8 runs Fri 25 Dec 2026: 8 runs Sat 26 Dec 2026: 8 runs Sun 27 Dec 2026: 8 runs Mon 28 Dec 2026: 8 runs Tue 29 Dec 2026: 8 runs Wed 30 Dec 2026: 8 runs Thu 31 Dec 2026: 8 runs Jan Fri 1 Jan 2027: 8 runs Sat 2 Jan 2027: 8 runs Sun 3 Jan 2027: 8 runs Mon 4 Jan 2027: 8 runs Tue 5 Jan 2027: 8 runs Wed 6 Jan 2027: 8 runs Thu 7 Jan 2027: 8 runs Fri 8 Jan 2027: 8 runs Sat 9 Jan 2027: 8 runs Sun 10 Jan 2027: 8 runs Mon 11 Jan 2027: 8 runs Tue 12 Jan 2027: 8 runs Wed 13 Jan 2027: 8 runs Thu 14 Jan 2027: 8 runs Fri 15 Jan 2027: 8 runs Sat 16 Jan 2027: 8 runs Sun 17 Jan 2027: 8 runs Mon 18 Jan 2027: 8 runs Tue 19 Jan 2027: 8 runs Wed 20 Jan 2027: 8 runs Thu 21 Jan 2027: 8 runs Fri 22 Jan 2027: 8 runs Sat 23 Jan 2027: 8 runs Sun 24 Jan 2027: 8 runs Mon 25 Jan 2027: 8 runs Tue 26 Jan 2027: 8 runs Wed 27 Jan 2027: 8 runs Thu 28 Jan 2027: 8 runs Fri 29 Jan 2027: 8 runs Sat 30 Jan 2027: 8 runs Sun 31 Jan 2027: 8 runs Feb Mon 1 Feb 2027: 8 runs Tue 2 Feb 2027: 8 runs Wed 3 Feb 2027: 8 runs Thu 4 Feb 2027: 8 runs Fri 5 Feb 2027: 8 runs Sat 6 Feb 2027: 8 runs Sun 7 Feb 2027: 8 runs Mon 8 Feb 2027: 8 runs Tue 9 Feb 2027: 8 runs Wed 10 Feb 2027: 8 runs Thu 11 Feb 2027: 8 runs Fri 12 Feb 2027: 8 runs Sat 13 Feb 2027: 8 runs Sun 14 Feb 2027: 8 runs Mon 15 Feb 2027: 8 runs Tue 16 Feb 2027: 8 runs Wed 17 Feb 2027: 8 runs Thu 18 Feb 2027: 8 runs Fri 19 Feb 2027: 8 runs Sat 20 Feb 2027: 8 runs Sun 21 Feb 2027: 8 runs Mon 22 Feb 2027: 8 runs Tue 23 Feb 2027: 8 runs Wed 24 Feb 2027: 8 runs Thu 25 Feb 2027: 8 runs Fri 26 Feb 2027: 8 runs Sat 27 Feb 2027: 8 runs Sun 28 Feb 2027: 8 runs Mar Mon 1 Mar 2027: 8 runs Tue 2 Mar 2027: 8 runs Wed 3 Mar 2027: 8 runs Thu 4 Mar 2027: 8 runs Fri 5 Mar 2027: 8 runs Sat 6 Mar 2027: 8 runs Sun 7 Mar 2027: 8 runs Mon 8 Mar 2027: 8 runs Tue 9 Mar 2027: 8 runs Wed 10 Mar 2027: 8 runs Thu 11 Mar 2027: 8 runs Fri 12 Mar 2027: 8 runs Sat 13 Mar 2027: 8 runs Sun 14 Mar 2027: 8 runs Mon 15 Mar 2027: 8 runs Tue 16 Mar 2027: 8 runs Wed 17 Mar 2027: 8 runs Thu 18 Mar 2027: 8 runs Fri 19 Mar 2027: 8 runs Sat 20 Mar 2027: 8 runs Sun 21 Mar 2027: 8 runs Mon 22 Mar 2027: 8 runs Tue 23 Mar 2027: 8 runs Wed 24 Mar 2027: 8 runs Thu 25 Mar 2027: 8 runs Fri 26 Mar 2027: 8 runs Sat 27 Mar 2027: 8 runs Sun 28 Mar 2027: 8 runs Mon 29 Mar 2027: 8 runs Tue 30 Mar 2027: 8 runs Wed 31 Mar 2027: 8 runs Apr Thu 1 Apr 2027: 8 runs Fri 2 Apr 2027: 8 runs Sat 3 Apr 2027: 8 runs Sun 4 Apr 2027: 8 runs Mon 5 Apr 2027: 8 runs Tue 6 Apr 2027: 8 runs Wed 7 Apr 2027: 8 runs Thu 8 Apr 2027: 8 runs Fri 9 Apr 2027: 8 runs Sat 10 Apr 2027: 8 runs Sun 11 Apr 2027: 8 runs Mon 12 Apr 2027: 8 runs Tue 13 Apr 2027: 8 runs Wed 14 Apr 2027: 8 runs Thu 15 Apr 2027: 8 runs Fri 16 Apr 2027: 8 runs Sat 17 Apr 2027: 8 runs Sun 18 Apr 2027: 8 runs Mon 19 Apr 2027: 8 runs Tue 20 Apr 2027: 8 runs Wed 21 Apr 2027: 8 runs Thu 22 Apr 2027: 8 runs Fri 23 Apr 2027: 8 runs Sat 24 Apr 2027: 8 runs Sun 25 Apr 2027: 8 runs Mon 26 Apr 2027: 8 runs Tue 27 Apr 2027: 8 runs Wed 28 Apr 2027: 8 runs Thu 29 Apr 2027: 8 runs Fri 30 Apr 2027: 8 runs May Sat 1 May 2027: 8 runs Sun 2 May 2027: 8 runs Mon 3 May 2027: 8 runs Tue 4 May 2027: 8 runs Wed 5 May 2027: 8 runs Thu 6 May 2027: 8 runs Fri 7 May 2027: 8 runs Sat 8 May 2027: 8 runs Sun 9 May 2027: 8 runs Mon 10 May 2027: 8 runs Tue 11 May 2027: 8 runs Wed 12 May 2027: 8 runs Thu 13 May 2027: 8 runs Fri 14 May 2027: 8 runs Sat 15 May 2027: 8 runs Sun 16 May 2027: 8 runs Mon 17 May 2027: 8 runs Tue 18 May 2027: 8 runs Wed 19 May 2027: 8 runs Thu 20 May 2027: 8 runs Fri 21 May 2027: 8 runs Sat 22 May 2027: 8 runs Sun 23 May 2027: 8 runs Mon 24 May 2027: 8 runs Tue 25 May 2027: 8 runs Wed 26 May 2027: 8 runs Thu 27 May 2027: 8 runs Fri 28 May 2027: 8 runs Sat 29 May 2027: 8 runs Sun 30 May 2027: 8 runs Mon 31 May 2027: 8 runs Jun Tue 1 Jun 2027: 8 runs Wed 2 Jun 2027: 8 runs Thu 3 Jun 2027: 8 runs Fri 4 Jun 2027: 8 runs Sat 5 Jun 2027: 8 runs Sun 6 Jun 2027: 8 runs Mon 7 Jun 2027: 8 runs Tue 8 Jun 2027: 8 runs Wed 9 Jun 2027: 8 runs Thu 10 Jun 2027: 8 runs Fri 11 Jun 2027: 8 runs Sat 12 Jun 2027: 8 runs Sun 13 Jun 2027: 8 runs Mon 14 Jun 2027: 8 runs Tue 15 Jun 2027: 8 runs Wed 16 Jun 2027: 8 runs Thu 17 Jun 2027: 8 runs Fri 18 Jun 2027: 8 runs Sat 19 Jun 2027: 8 runs Sun 20 Jun 2027: 8 runs Mon 21 Jun 2027: 8 runs Tue 22 Jun 2027: 8 runs Wed 23 Jun 2027: 8 runs Thu 24 Jun 2027: 8 runs Fri 25 Jun 2027: 8 runs Sat 26 Jun 2027: 8 runs Sun 27 Jun 2027: 8 runs Mon 28 Jun 2027: 8 runs Tue 29 Jun 2027: 8 runs Wed 30 Jun 2027: 8 runs Jul Thu 1 Jul 2027: 8 runs Fri 2 Jul 2027: 8 runs Sat 3 Jul 2027: 8 runs Sun 4 Jul 2027: 8 runs Mon 5 Jul 2027: 8 runs Tue 6 Jul 2027: 8 runs Wed 7 Jul 2027: 8 runs Thu 8 Jul 2027: 8 runs Fri 9 Jul 2027: 8 runs Sat 10 Jul 2027: 8 runs Sun 11 Jul 2027: 8 runs Mon 12 Jul 2027: 8 runs Tue 13 Jul 2027: 8 runs Wed 14 Jul 2027: 8 runs Thu 15 Jul 2027: 8 runs Fri 16 Jul 2027: 8 runs Sat 17 Jul 2027: 8 runs Sun 18 Jul 2027: 8 runs Mon 19 Jul 2027: 8 runs Tue 20 Jul 2027: 8 runs Wed 21 Jul 2027: 8 runs Thu 22 Jul 2027: 8 runs Fri 23 Jul 2027: 8 runs Sat 24 Jul 2027: 8 runs Sun 25 Jul 2027: 8 runs Mon 26 Jul 2027: 8 runs Tue 27 Jul 2027: 8 runs Wed 28 Jul 2027: 8 runs Thu 29 Jul 2027: 8 runs Fri 30 Jul 2027: 8 runs Sat 31 Jul 2027: 8 runs Aug Sun 1 Aug 2027: 8 runs Mon 2 Aug 2027: 8 runs Tue 3 Aug 2027: 8 runs Wed 4 Aug 2027: 8 runs Thu 5 Aug 2027: 8 runs Fri 6 Aug 2027: 8 runs Sat 7 Aug 2027: 8 runs Sun 8 Aug 2027: 8 runs Mon 9 Aug 2027: 8 runs Tue 10 Aug 2027: 8 runs Wed 11 Aug 2027: 8 runs Thu 12 Aug 2027: 8 runs Fri 13 Aug 2027: 8 runs Sat 14 Aug 2027: 8 runs Sun 15 Aug 2027: 8 runs Mon 16 Aug 2027: 8 runs Tue 17 Aug 2027: 8 runs Wed 18 Aug 2027: 8 runs Thu 19 Aug 2027: 8 runs Fri 20 Aug 2027: 8 runs Sat 21 Aug 2027: 8 runs Sun 22 Aug 2027: 8 runs Mon 23 Aug 2027: 8 runs Tue 24 Aug 2027: 8 runs Wed 25 Aug 2027: 8 runs Thu 26 Aug 2027: 8 runs Fri 27 Aug 2027: 8 runs Sat 28 Aug 2027: 8 runs Sun 29 Aug 2027: 8 runs Mon 30 Aug 2027: 8 runs Tue 31 Aug 2027: 8 runs Sep Wed 1 Sep 2027: 8 runs Thu 2 Sep 2027: 8 runs Fri 3 Sep 2027: 8 runs Sat 4 Sep 2027: 8 runs Sun 5 Sep 2027: 8 runs Mon 6 Sep 2027: 8 runs Tue 7 Sep 2027: 8 runs Wed 8 Sep 2027: 8 runs Thu 9 Sep 2027: 8 runs Fri 10 Sep 2027: 8 runs Sat 11 Sep 2027: 8 runs Sun 12 Sep 2027: 8 runs Mon 13 Sep 2027: 8 runs Tue 14 Sep 2027: 8 runs Wed 15 Sep 2027: 8 runs Thu 16 Sep 2027: 8 runs Fri 17 Sep 2027: 8 runs Sat 18 Sep 2027: 8 runs Sun 19 Sep 2027: 8 runs Mon 20 Sep 2027: 8 runs Tue 21 Sep 2027: 8 runs Wed 22 Sep 2027: 8 runs Thu 23 Sep 2027: 8 runs Fri 24 Sep 2027: 8 runs Sat 25 Sep 2027: 8 runs Sun 26 Sep 2027: 8 runs Mon 27 Sep 2027: 8 runs Tue 28 Sep 2027: 8 runs Wed 29 Sep 2027: 8 runs Thu 30 Sep 2027: 8 runs Oct Fri 1 Oct 2027: 8 runs Sat 2 Oct 2027: 8 runs Sun 3 Oct 2027: 8 runs Mon 4 Oct 2027: 8 runs Tue 5 Oct 2027: 8 runs Wed 6 Oct 2027: 8 runs Thu 7 Oct 2027: 8 runs Fri 8 Oct 2027: 8 runs Sat 9 Oct 2027: 8 runs Sun 10 Oct 2027: 8 runs Mon 11 Oct 2027: 8 runs Tue 12 Oct 2027: 8 runs Wed 13 Oct 2027: 8 runs Thu 14 Oct 2027: 8 runs Fri 15 Oct 2027: 8 runs Sat 16 Oct 2027: 8 runs Sun 17 Oct 2027: 8 runs Mon 18 Oct 2027: 8 runs Tue 19 Oct 2027: 8 runs Wed 20 Oct 2027: 8 runs Thu 21 Oct 2027: 8 runs Fri 22 Oct 2027: 8 runs Sat 23 Oct 2027: 8 runs Sun 24 Oct 2027: 8 runs Mon 25 Oct 2027: 8 runs Tue 26 Oct 2027: 8 runs Wed 27 Oct 2027: 8 runs Thu 28 Oct 2027: 8 runs Fri 29 Oct 2027: 8 runs
What to know The breakdown below is the first line. 90 minutes divides a day evenly (16 runs), so the pattern repeats cleanly every day.
Intervals that do not divide 24 hours evenly (every 7 hours, every 100 minutes) cannot be kept exactly by cron. Use a systemd timer (OnUnitActiveSec=100min) or a scheduler that works with intervals.
Variations
30 1-22/3 * * *the second line: 01:30, 04:30 … 22:30 At minute 30 past 01:00, 04:00, 07:00, 10:00, 13:00, 16:00, 19:00 and 22:00.
0 */3 * * *every 3 hours, if 90 minutes was negotiable At minute 0 past every 3rd hour (00:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00 and 21:00).
Gotchas Put both lines in the same crontab with the same command, and keep them together with a comment so nobody deletes one. ← Explain any cron expression
