Cron Syntax

Cron Syntax

Chronos uses a standard Unix-like cron syntax with 5 fields.

┌───────────── minute (0 - 59)
│ ┌───────────── hour (0 - 23)
│ │ ┌───────────── day of month (1 - 31)
│ │ │ ┌───────────── month (1 - 12)
│ │ │ │ ┌───────────── day of week (0 - 7) (Sunday is 0 or 7)
│ │ │ │ │
* * * * *

Supported Combinations

Character	Description	Example	Meaning
*	Any value	*	Every minute/hour/day...
,	List separator	1,3,5	At 1, 3, AND 5
-	Range	1-5	From 1 to 5 inclusive
/	Step values	*/15	Every 15 units

Examples

Expression	Description
0 9 * * *	Every day at 9:00 AM
*/15 * * * *	Every 15 minutes
0 0 * * 1	Every Monday at midnight
0 9-17 * * 1-5	Every hour from 9 AM to 5 PM, Mon-Fri

Union Behavior

When both Day of Month and Day of Week are specified (not *), Chronos uses OR logic (Union).

Example: 0 9 1 * 1 fires on:

• The 1st of the month
• OR
• Any Monday