Cron expressions syntax

Tom Santiago

Updated March 19, 2024 09:37

Cron schedule syntax

All Celigo flows use the cron style of scheduling. This document describes cron syntax and provides use case examples.

Cron schedules have five positions referenced by five asterisks:

*	*	*	*	*
Minute (0-59)	Hour (0-23)	Day of the month (1-31)	Month (1-12)	Day of the week (0-6)

Position

Description

Minute

The first position is for the minute. This is in 15 minute intervals since the script that checks the schedule runs every 15 minutes.

The interval ranges in an hour are:

0-14 - the script runs within the first 15 minutes of the hour.
15-29 - the script runs after the first 15 minutes, but before the first 30 minutes of the hour.
30-44 - the script runs after the first 30 minutes, but before the first 45 minutes of the hour.
45-59 - the script runs within the last 15 minutes of the hour.
0-29 - the script runs twice within the first 30 minutes of the hour.
0-44 - the script runs 3 times within the first 45 minutes of the hour.
An asterisk (*) indicates any minute of the hour, and is equivalent to 0-59. This runs 4 times within the hour.

Hour

The second position is the hour of the day. This is expressed in military format 0-23 where 0 is midnight (12 AM) and 23 is 11 PM. If 11,23 is entered, this means the script runs at 11 AM and 11 PM.

Day

The third position is the day of the month from 1-31. If 15 is entered, the script only runs on the 15th day of the month. Enter an asterisk (*) to let it run every day.

Month

The fourth position specifies the months to run. This is expressed as 1-12, where 1 is January and 12 is December. Enter an asterisk (*) to run the script every month.

Weekday

The fifth position is the day of the week. Use MON, TUE, WED, THU, FRI, SAT, SUN to represent each day of the week.

Weekdays can also be referenced with the following number system:

0	1	2	3	4	5	6
Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday

Examples:

* * * * * Every minute
0 * * * * Every hour
0 0 * * * Every day at 12:00AM
0 0 ? * FRI At 12:00AM only on Friday
0 0 1 * ? At 12:00AM on the first day of the month

Note: A cron expression can't simultaneously use day (third position) and weekday (fifth position). Enter a question mark (?) for the unused position.

Run on the first 15 minutes of the hour every 11 AM and 11 PM of every day and every month for any day of the week.

 0-14 11,23 ? * MON,TUE,WED,THU,FRI,SAT,SUN

Run on the first part of the hour at 5 AM every 15th day of the month.

0-14 5 15 * ?

Run at the bottom of the hour at 1 PM and 5 PM every month only on Mondays, Wednesdays, and Fridays.

30-44 13,17 ? * MON,WED,FRI

Run every 15 minutes everyday.

0-14,15-29,30-44,45-59 * ? * *

0-14 12 ? * 0-6

Run at 5 PM on weekdays.

0-14 17 ? * MON-FRI

Run on the first day of the month at 7 AM.

0-14 7 1 * ?

Take the Advanced Flow Builder class to learn more about this topic.