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Elements of the flow - Cron Trigger

The cronjob triggers a flow according to a schedule defined by the cronjob expression. This allows processes in GroupAlarm to be automated at specified times. A classic example of such a process is a regular test alarm.

💡 The cronjob for the flow can be added to your organisation via the Automated tasks extension under Admin ⇾ Extensions.

Configuration

1️⃣ In the schedule input field, specify the cron job expression to be executed. The expression contains all information regarding the time of execution. The syntax consists of five intervals. The smallest possible interval is per minute, followed by per hour, the day of the month, the month and the day of the week. A detailed description and examples of the syntax can be found below.

2️⃣ Once you have specified a cronjob expression, you will see a list of the first three executions of the cronjob. This gives you an overview of whether your syntax is working as intended.

Cron fields

Each asterisk (*) in the schedule corresponds to a field in the table and stands for ‘all’ permissible values for that field.

Position	Field	Permissible values	Description
1	Minutes	`*` `/` `,` `-` `0-59`	The minute of the hour at which the command is executed.
2	Hours	`*` `/` `0-23`	The hour of the day at which the command is executed (0 is midnight).
3	Day of the month	`*` `/` `1-31` `L` `?`	The day of the month on which the command is executed.
4	Month	`*` `/` `1-12`	The month of the year in which the command is executed.
5	Day of the week	`*` `/` `0-7` `L` `#` `?`	The day of the week on which the command is executed. Both `0` and `7` represent Sunday.

Cron syntax overview

Symbol	Description	Example
`*`	Corresponds to all values in the field.	`*` in the minutes field means ‘every minute’.
`,`	Lists values separated by commas.	`1,3,5` in the hour field means ‘at 1, 3 and 5 o'clock’.
`-`	Defines a range of values.	`8-12` in the hour field means ‘every hour from 8 o'clock to 12 o'clock’.
`/`	Defines intervals. The first `*` or number is the starting value.	`*/5` in the minute field means ‘every 5 minutes’.
`?`	Used instead of `*` to indicate that a field should be ignored. Useful for specifying either the day of the week or the day of the month without the other interfering.	`0 0 10 * ?` triggers on the 10th of each month, regardless of the day of the week.
`L`	‘Last’. Specifies the last day of the month or the last day of the week in the month.	`L` in the day of the month field means ‘the last day of the month’. `5L` in the day of the month field means ‘the last Thursday of the month’.
`#`	‘Nth day of the week of the month’. Specifies the Nth occurrence of a particular day of the week.	`6#3` in the day of the week field means ‘the third Friday of the month’.

Special notes:

? and *: You can use ? either for the day of the month or for the day of the week, but not for both at the same time. It serves to resolve the conflict logic that exists in the standard Unix cron syntax.
L: When L is used in the day of the week field, it can be combined with a number. For example, 5L means the last Thursday of the month.
#: The syntax is day of the week#occurrence. For example, 1#2 means the second Monday. (1 stands for Monday).

Common cron examples

Cron expression	Description
`* * * * *`	Every minute.
`0 12 * * *`	Every day at 12:00 noon.
`0 /2 * *`	Every two hours.
`0 12 * * 1-5`	Every working day at 12:00 noon.
`0 0 * * 0`	Weekly, at midnight from Saturday to Sunday.
`0 0 1 * *`	Monthly, on the first day of the month at 00:00.
`0 12 * * 6#1`	On the first Saturday of the month at 12:00
`0 0 1 1 *`	Annually, on 1 January at 00:00.
`/15 * * *`	Every 15 minutes.
`0 9-17 * * 1-5`	Every hour between 9:00 and 17:00, Monday to Friday only.

Updated on: 19/08/2025

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