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

Specifies when and how long an alarm mute rule is active.

The schedule uses either a cron expression for recurring mute windows or an at expression for one-time mute windows. When the schedule activates, the mute rule mutes alarm actions for the specified duration.

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

 ** Duration **   <a name="ACW-Type-Schedule-Duration"></a>
The length of time that alarms remain muted when the schedule activates. The duration must be between 1 and 50 characters in length.  
Specify the duration using ISO 8601 duration format with a minimum of 1 minute (`PT1M`) and maximum of 15 days (`P15D`).  
Examples:  
+  `PT4H` - 4 hours for weekly system maintenance
+  `P2DT12H` - 2 days and 12 hours for weekend muting from Friday 6:00 PM to Monday 6:00 AM
+  `PT6H` - 6 hours for monthly database maintenance
+  `PT2H` - 2 hours for nightly backup operations
+  `P7D` - 7 days for annual company shutdown
The duration begins when the schedule expression time is reached. For recurring schedules, the duration applies to each occurrence.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 50.  
Required: Yes

 ** Expression **   <a name="ACW-Type-Schedule-Expression"></a>
The schedule expression that defines when the mute rule activates. The expression must be between 1 and 256 characters in length.  
You can use one of two expression formats:  
+  **Cron expressions** - For recurring mute windows. Format: `cron(Minutes Hours Day-of-month Month Day-of-week)` 

  Examples:
  +  `cron(0 2 * * *)` - Activates daily at 2:00 AM
  +  `cron(0 2 * * SUN)` - Activates every Sunday at 2:00 AM for weekly system maintenance
  +  `cron(0 1 1 * *)` - Activates on the first day of each month at 1:00 AM for monthly database maintenance
  +  `cron(0 18 * * FRI)` - Activates every Friday at 6:00 PM
  +  `cron(0 23 * * *)` - Activates every day at 11:00 PM during nightly backup operations

  The characters `*`, `-`, and `,` are supported in all fields. English names can be used for the month (JAN-DEC) and day of week (SUN-SAT) fields.
+  **At expressions** - For one-time mute windows. Format: `at(yyyy-MM-ddThh:mm)` 

  Examples:
  +  `at(2024-05-10T14:00)` - Activates once on May 10, 2024 at 2:00 PM during an active incident response session
  +  `at(2024-12-23T00:00)` - Activates once on December 23, 2024 at midnight during annual company shutdown
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 256.  
Required: Yes

 ** Timezone **   <a name="ACW-Type-Schedule-Timezone"></a>
The time zone to use when evaluating the schedule expression. The time zone must be between 1 and 50 characters in length.  
Specify the time zone using standard timezone identifiers (for example, `America/New_York`, `Europe/London`, or `Asia/Tokyo`).  
If you don't specify a time zone, UTC is used by default. The time zone affects how cron and at expressions are interpreted, as well as start and expire dates you specify  
Examples:  
+  `America/New_York` - Eastern Time (US)
+  `America/Los_Angeles` - Pacific Time (US)
+  `Europe/London` - British Time
+  `Asia/Tokyo` - Japan Standard Time
+  `UTC` - Coordinated Universal Time
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 50.  
Required: No

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

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/monitoring-2010-08-01/Schedule) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/monitoring-2010-08-01/Schedule) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/monitoring-2010-08-01/Schedule)