> For the complete documentation index, see [llms.txt](https://docs.senpiper.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.senpiper.com/alarm-builder/alarms-for-custom-data-exports/add-a-new-alarm/define-schedule.md). # Define Schedule Step 3 of setting up a custom alarm is configuring a schedule for when the alarm should be triggered.

We can define a fixed schedule for the alerts to be sent to the user. 1\. Select the date & time when to initiate the alarm 2\. After selecting the initiation date & time, select the execution of an alarm event - **Once**, or **Repeated.** To send out the data exports at regular intervals, select **Repeated**. On selecting **Repeated**, we will ask to select the time duration after which we want to send out the notifications. {% hint style="info" %} The alternative way to define a schedule for alerts is by providing a CRON expression. A cron expression is a string comprising a number of fields that represent the individual details of a schedule. For more information on CRON expressions, see {% endhint %}