# Schedule
<a name="API_Schedule"></a>

A schedule configures when and how often a pipeline will automatically create a new image.

## Contents
<a name="API_Schedule_Contents"></a>

 ** autoDisablePolicy **   <a name="imagebuilder-Type-Schedule-autoDisablePolicy"></a>
The policy that configures when Image Builder should automatically disable a pipeline that is failing.  
Type: [AutoDisablePolicy](API_AutoDisablePolicy.md) object  
Required: No

 ** pipelineExecutionStartCondition **   <a name="imagebuilder-Type-Schedule-pipelineExecutionStartCondition"></a>
The start condition configures when the pipeline should trigger a new image build, as follows. If no value is set Image Builder defaults to `EXPRESSION_MATCH_AND_DEPENDENCY_UPDATES_AVAILABLE`.  
+  `EXPRESSION_MATCH_AND_DEPENDENCY_UPDATES_AVAILABLE` (default) – When you use semantic version filters on the base image or components in your image recipe, EC2 Image Builder builds a new image only when there are new versions of the base image or components in your recipe that match the filter.
**Note**  
For semantic version syntax, see [CreateComponent](https://docs.amazonaws.cn/imagebuilder/latest/APIReference/API_CreateComponent.html).
+  `EXPRESSION_MATCH_ONLY` – This condition builds a new image every time the CRON expression matches the current time.
Type: String  
Valid Values: `EXPRESSION_MATCH_ONLY | EXPRESSION_MATCH_AND_DEPENDENCY_UPDATES_AVAILABLE`   
Required: No

 ** scheduleExpression **   <a name="imagebuilder-Type-Schedule-scheduleExpression"></a>
The cron expression determines how often EC2 Image Builder evaluates your `pipelineExecutionStartCondition`.  
For information on how to format a cron expression in Image Builder, see [Use cron expressions in EC2 Image Builder](https://docs.amazonaws.cn/imagebuilder/latest/userguide/image-builder-cron.html).  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 1024.  
Required: No

 ** timezone **   <a name="imagebuilder-Type-Schedule-timezone"></a>
The timezone that applies to the scheduling expression. For example, "Etc/UTC", "America/Los\$1Angeles" in the [IANA timezone format](https://www.joda.org/joda-time/timezones.html). If not specified this defaults to UTC.  
Type: String  
Length Constraints: Minimum length of 3. Maximum length of 100.  
Pattern: `[a-zA-Z0-9]{2,}(?:\/[a-zA-Z0-9-_+]+)*`   
Required: No

## See Also
<a name="API_Schedule_SeeAlso"></a>

For more information about using this API in one of the language-specific Amazon SDKs, see the following:
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/imagebuilder-2019-12-02/Schedule) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/imagebuilder-2019-12-02/Schedule) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/imagebuilder-2019-12-02/Schedule)