github.com/smintz/nomad@v0.8.3/website/source/docs/job-specification/periodic.html.md (about) 1 --- 2 layout: "docs" 3 page_title: "periodic Stanza - Job Specification" 4 sidebar_current: "docs-job-specification-periodic" 5 description: |- 6 The "periodic" stanza allows a job to run at fixed times, dates, or intervals. 7 The easiest way to think about the periodic scheduler is "Nomad cron" or 8 "distributed cron". 9 --- 10 11 # `periodic` Stanza 12 13 <table class="table table-bordered table-striped"> 14 <tr> 15 <th width="120">Placement</th> 16 <td> 17 <code>job -> **periodic**</code> 18 </td> 19 </tr> 20 </table> 21 22 The `periodic` stanza allows a job to run at fixed times, dates, or intervals. 23 The easiest way to think about the periodic scheduler is "Nomad cron" or 24 "distributed cron". 25 26 ```hcl 27 job "docs" { 28 periodic { 29 cron = "*/15 * * * * *" 30 prohibit_overlap = true 31 } 32 } 33 ``` 34 35 The periodic expression by default evaluates in the **UTC timezone** to ensure 36 consistent evaluation when Nomad spans multiple time zones. 37 38 ## `periodic` Requirements 39 40 - The job's [scheduler type][batch-type] must be `batch`. 41 42 ## `periodic` Parameters 43 44 - `cron` `(string: <required>)` - Specifies a cron expression configuring the 45 interval to launch the job. In addition to [cron-specific formats][cron], this 46 option also includes predefined expressions such as `@daily` or `@weekly`. 47 48 - `prohibit_overlap` `(bool: false)` - Specifies if this job should wait until 49 previous instances of this job have completed. This only applies to this job; 50 it does not prevent other periodic jobs from running at the same time. 51 52 - `time_zone` `(string: "UTC")` - Specifies the time zone to evaluate the next 53 launch interval against. This is useful when wanting to account for day light 54 savings in various time zones. The time zone must be parsable by Golang's 55 [LoadLocation](https://golang.org/pkg/time/#LoadLocation). 56 57 ## `periodic` Examples 58 59 The following examples only show the `periodic` stanzas. Remember that the 60 `periodic` stanza is only valid in the placements listed above. 61 62 ### Run Daily 63 64 This example shows running a periodic job daily: 65 66 ```hcl 67 periodic { 68 cron = "@daily" 69 } 70 ``` 71 72 ### Set Time Zone 73 74 This example shows setting a time zone for the periodic job to evaluate in: 75 76 ```hcl 77 periodic { 78 cron = "*/15 * * * * *" 79 time_zone = "America/New_York" 80 } 81 ``` 82 83 [batch-type]: /docs/job-specification/job.html#type "Batch scheduler type" 84 [cron]: https://github.com/gorhill/cronexpr#implementation "List of cron expressions"