What are ScheduledTask cron rules-OpenSearch(Open Search)-阿里云帮助中心

The cron field in ScheduledTask defines the scheduling rule for a scheduled task. OpenSearch uses the node-schedule component to run scheduled tasks, so the scheduling rule must follow the cron format that node-schedule accepts.

Field reference

A cron expression contains five or six space-separated fields, listed left to right:

second  minute  hour  day-of-month  month  day-of-week
  s       i       h        d           m        w

The second field is optional. In most cases, omit it and write a five-field expression.

Field	Abbreviation	Valid values	Required
Second	`s`	0–59	No
Minute	`i`	0–59	Yes
Hour	`h`	0–23 (24-hour clock)	Yes
Day of month	`d`	1–31	Yes
Month	`m`	1–12	Yes
Day of week	`w`	0–7 (0 and 7 both mean Sunday)	Yes

Special characters

Character	Meaning	Example
`*`	Every unit — matches all valid values	`* * * * *` runs every minute
`a-b`	Range — runs during the specified interval	`9-17` in the hour field runs every hour from 9 AM to 5 PM
`*/n`	Step — runs every n units	`*/5` in the minute field runs every 5 minutes
`a,b,c`	List — runs at each specified value	`1,15` in the day-of-month field runs on the 1st and 15th of each month

Examples

Expression	Runs
`* * * * *`	Every minute
`0 * * * *`	Every hour, on the hour
`0 9 * * *`	Every day at 9:00 AM
`0 9 * * 1`	Every Monday at 9:00 AM
`0 9 1 * *`	On the 1st of every month at 9:00 AM
`/5 * * * *`	Every 5 seconds (six-field expression with second field)
`0 9-17 * * 1-5`	Every hour from 9 AM to 5 PM, Monday through Friday

What's next

For the full node-schedule cron syntax, see the node-schedule documentation.