# OffPeakWindow


A custom 10-hour, low-traffic window during which OpenSearch Service can perform mandatory configuration changes on the domain. These actions can include scheduled service software updates and blue/green Auto-Tune enhancements. OpenSearch Service will schedule these actions during the window that you specify.

If you don't specify a window start time, it defaults to 10:00 P.M. local time.

For more information, see [Defining off-peak maintenance windows for Amazon OpenSearch Service](https://docs.aws.amazon.com/opensearch-service/latest/developerguide/off-peak.html).

## Contents


 ** WindowStartTime **   <a name="opensearchservice-Type-OffPeakWindow-WindowStartTime"></a>
A custom start time for the off-peak window, in Coordinated Universal Time (UTC). The window length will always be 10 hours, so you can't specify an end time. For example, if you specify 11:00 P.M. UTC as a start time, the end time will automatically be set to 9:00 A.M.  
Type: [WindowStartTime](API_WindowStartTime.md) object  
Required: No

## See Also


For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/opensearch-2021-01-01/OffPeakWindow) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/opensearch-2021-01-01/OffPeakWindow) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/opensearch-2021-01-01/OffPeakWindow)