# Create custom event windows for scheduled events that affect your Amazon EC2 instances
<a name="event-windows"></a>

You can define custom event windows that recur weekly for scheduled events that reboot, stop, or terminate your Amazon EC2 instances. You can associate one or more instances with an event window. If a scheduled event for those instances is planned, AWS will schedule the events within the associated event window.

You can use event windows to maximize workload availability by specifying event windows that occur during off-peak periods for your workload. You can also align the event windows with your internal maintenance schedules.

You define an event window by specifying a set of time ranges. The minimum time range is 2 hours. The combined time ranges must total at least 4 hours.

You can associate one or more instances with an event window by using either instance IDs or instance tags. You can also associate Dedicated Hosts with an event window by using the host ID.

**Warning**  
Event windows are applicable only for scheduled events that stop, reboot, or terminate instances.  
Event windows are not applicable for:  
Expedited scheduled events and network maintenance events. 
Unscheduled maintenance such as [automatic instance recovery](ec2-instance-recover.md) and unplanned reboots.

**Topics**
+ [

## Considerations
](#event-windows-considerations)
+ [

## Create an event window
](#create-event-windows)
+ [

## Associate a target with an event window
](#associate-target-event-window)
+ [

## Disassociate a target from an event window
](#disassociate-target-event-window)
+ [

## Modify an event window
](#modify-event-windows)
+ [

## Delete an event window
](#delete-event-windows)

## Considerations
<a name="event-windows-considerations"></a>
+ All event window times are in UTC.
+ An event window can contain multiple time ranges. While each individual range must be at least 2 hours, the total duration across all ranges must be at least 4 hours.
+ Only one target type (instance ID, Dedicated Host ID, or instance tag) can be associated with an event window.
+ A target (instance ID, Dedicated Host ID, or instance tag) can only be associated with one event window.
+ A maximum of 100 instance IDs, or 50 Dedicated Host IDs, or 50 instance tags can be associated with an event window. The instance tags can be associated with any number of instances.
+ A maximum of 200 event windows can be created per AWS Region.
+ Multiple instances that are associated with event windows can potentially have scheduled events occur at the same time.
+ If AWS has already scheduled an event, modifying an event window won't change the time of the scheduled event. If the event has a deadline date, you can [reschedule the event](reschedule-event.md).
+ You can stop and start an instance before the scheduled event. This migrates the instance to a new host and clears the event.

## Create an event window
<a name="create-event-windows"></a>

You can create one or more event windows. For each event window, you specify one or more blocks of time. For example, you can create an event window with blocks of time that occur every day at 4 AM for 2 hours. Or you can create an event window with blocks of time that occur on Sundays from 2 AM to 4 AM and on Wednesdays from 3 AM to 5 AM.

Event windows recur weekly until you delete them.

------
#### [ Console ]

**To create an event window**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation pane, choose **Events**.

1. Choose **Actions**, **Manage event windows**.

1. Choose **Create instance event window**.

1. For **Event window name**, enter a descriptive name for the event window.

1. For **Event window schedule**, choose to specify the blocks of time in the event window by using the cron schedule builder or by specifying time ranges.
   + If you choose **Cron schedule builder**, specify the following:

     1. For **Days (UTC)**, specify the days of the week on which the event window occurs.

     1. For **Start time (UTC)**, specify the time when the event window begins.

     1. For **Duration**, specify the duration of the blocks of time in the event window. The minimum duration per block of time is 2 hours. The minimum duration of the event window must equal or exceed 4 hours in total. All times are in UTC.
   + If you choose **Time ranges**, choose **Add new time range** and specify the start day and time and the end day and time. Repeat for each time range. The minimum duration per time range is 2 hours. The minimum duration for all time ranges combined must equal or exceed 4 hours in total.

1. (Optional) For **Target details**, associate one or more instances with the event window. Use instance IDs or instance tags to associate instances. Use host IDs to associate Dedicated Hosts. When these targets are scheduled for maintenance, the event will occur during this event window. 

   Note that you can create the event window without associating a target with the window. Later, you can modify the window to associate one or more targets.

1. (Optional) For **Event window tags**, choose **Add tag**, and enter the key and value for the tag. Repeat for each tag.

1. Choose **Create event window**.

------
#### [ AWS CLI ]

**To create an event window with a time range**  
Use the [create-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/create-instance-event-window.html) command.

```
aws ec2 create-instance-event-window \
    --time-range StartWeekDay=monday,StartHour=2,EndWeekDay=wednesday,EndHour=8 \
    --tag-specifications "ResourceType=instance-event-window,Tags=[{Key=K1,Value=V1}]" \
    --name myEventWindowName
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "TimeRanges": [
            {
                "StartWeekDay": "monday",
                "StartHour": 2,
                "EndWeekDay": "wednesday",
                "EndHour": 8
            }
        ],
        "Name": "myEventWindowName",
        "State": "creating",
        "Tags": [
            {
                "Key": "K1",
                "Value": "V1"
            }
        ]
    }
}
```

**To create an event window with a cron expression**  
Use the [create-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/create-instance-event-window.html) command.

```
aws ec2 create-instance-event-window \
    --cron-expression "* 21-23 * * 2,3" \
    --tag-specifications "ResourceType=instance-event-window,Tags=[{Key=K1,Value=V1}]" \
    --name myEventWindowName
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "State": "creating",
        "Tags": [
            {
                "Key": "K1",
                "Value": "V1"
            }
        ]
    }
}
```

------
#### [ PowerShell ]

**To create an event window with a time range**  
Use the [New-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/New-EC2InstanceEventWindow.html) cmdlet.

```
$timeRange = New-Object Amazon.EC2.Model.InstanceEventWindowTimeRangeRequest
$timeRange.StartWeekDay = "monday"
$timeRange.EndWeekDay = "wednesday"
$timeRange.StartHour = 2
$timeRange.EndHour = 8
$tag = @{Key="key1"; Value="value1"}
$tagspec = New-Object Amazon.EC2.Model.TagSpecification
$tagspec.ResourceType = "instance-event-window"
$tagspec.Tags.Add($tag)
New-EC2InstanceEventWindow `
    -Name my-event-window `
    -TagSpecification $tagspec `
    -TimeRange @($timeRange)
```

The following is example output.

```
AssociationTarget     : 
CronExpression        : 
InstanceEventWindowId : iew-0abcdef1234567890
Name                  : my-event-window
State                 : creating
Tags                  : {key1}
TimeRanges            : {Amazon.EC2.Model.InstanceEventWindowTimeRange}
```

**To create an event window with a cron expression**  
Use the [New-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/New-EC2InstanceEventWindow.html) cmdlet.

```
$tag = @{Key="key1"; Value="value1"}
$tagspec = New-Object Amazon.EC2.Model.TagSpecification
$tagspec.ResourceType = "instance-event-window"
$tagspec.Tags.Add($tag)
New-EC2InstanceEventWindow `
    -Name my-event-window `
    -TagSpecification $tagspec`
    -CronExpression "* 21-23 * * 2,3"
```

The following is example output.

```
AssociationTarget     : 
CronExpression        : * 21-23 * * 2,3
InstanceEventWindowId : iew-0abcdef1234567890
Name                  : my-event-window
State                 : creating
Tags                  : {key1}
TimeRanges            : {}
```

------

## Associate a target with an event window
<a name="associate-target-event-window"></a>

After you create an event window, you can associate targets with the event window. You can associate only one type of target with an event window. You can specify instance IDs, Dedicated Host IDs, or instance tags.

------
#### [ Console ]

**To associate targets with an event window**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation pane, choose **Events**.

1. Select the event window to modify.

1. Choose **Actions**, **Modify instance event window**.

------
#### [ AWS CLI ]

**To associate instance tags with an event window**  
Use the [associate-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/associate-instance-event-window.html) command.

```
aws ec2 associate-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890 \
    --association-target "InstanceTags=[{Key=k2,Value=v2},{Key=k1,Value=v1}]"
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "AssociationTarget": {
            "InstanceIds": [],
            "Tags": [
                {
                    "Key": "k2",
                    "Value": "v2"
                },
                {
                    "Key": "k1",
                    "Value": "v1"
                }
            ],
            "DedicatedHostIds": []
        },
        "State": "creating"
    }
}
```

**To associate instance IDs with an event window**  
Use the [associate-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/associate-instance-event-window.html) command.

```
aws ec2 associate-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890 \
    --association-target "InstanceIds=i-1234567890abcdef0,i-0598c7d356eba48d7"
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "AssociationTarget": {
            "InstanceIds": [
                "i-1234567890abcdef0",
                "i-0598c7d356eba48d7"
            ],
            "Tags": [],
            "DedicatedHostIds": []
        },
        "State": "creating"
    }
}
```

**To associate a Dedicated Host with an event window**  
Use the [associate-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/associate-instance-event-window.html) command.

```
aws ec2 associate-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890 \
    --association-target "DedicatedHostIds=h-029fa35a02b99801d"
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "AssociationTarget": {
            "InstanceIds": [],
            "Tags": [],
            "DedicatedHostIds": [
                "h-029fa35a02b99801d"
            ]
        },
        "State": "creating"
    }
}
```

------
#### [ PowerShell ]

**To associate instance tags with an event window**  
Use the [Register-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Register-EC2InstanceEventWindow.html) cmdlet.

```
$tag1 = @{Key="key1"; Value="value1"}
$tag2 = @{Key="key2"; Value="value2"}
Register-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -AssociationTarget_InstanceTag @($tag1,$tag2)
```

**To associate instance IDs with an event window**  
Use the [Register-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Register-EC2InstanceEventWindow.html) cmdlet.

```
Register-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -AssociationTarget_InstanceId i-1234567890abcdef0, i-0598c7d356eba48d7
```

**To associate a Dedicated Host with an event window**  
Use the [Register-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Register-EC2InstanceEventWindow.html) cmdlet.

```
Register-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -AssociationTarget_DedicatedHostId h-029fa35a02b99801d
```

------

## Disassociate a target from an event window
<a name="disassociate-target-event-window"></a>

------
#### [ Console ]

**To disassociate targets with an event window**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation pane, choose **Events**.

1. Select the event window to modify.

1. Choose **Actions**, **Modify instance event window**.

------
#### [ AWS CLI ]

**To disassociate instance tags from an event window**  
Use the [disassociate-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference//ec2/disassociate-instance-event-window.html) command.

```
aws ec2 disassociate-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890 \
    --association-target "InstanceTags=[{Key=k2,Value=v2},{Key=k1,Value=v1}]"
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "AssociationTarget": {
            "InstanceIds": [],
            "Tags": [],
            "DedicatedHostIds": []
        },
        "State": "creating"
    }
}
```

**To disassociate instance IDs from an event window**  
Use the [disassociate-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/disassociate-instance-event-window.html) command.

```
aws ec2 disassociate-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890 \
    --association-target "InstanceIds=i-1234567890abcdef0,i-0598c7d356eba48d7"
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "AssociationTarget": {
            "InstanceIds": [],
            "Tags": [],
            "DedicatedHostIds": []
        },
        "State": "creating"
    }
}
```

**To disassociate a Dedicated Host from an event window**  
Use the [disassociate-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/disassociate-instance-event-window.html) command.

```
aws ec2 disassociate-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890 \
    --association-target DedicatedHostIds=h-029fa35a02b99801d
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "AssociationTarget": {
            "InstanceIds": [],
            "Tags": [],
            "DedicatedHostIds": []
        },
        "State": "creating"
    }
}
```

------
#### [ PowerShell ]

**To disassociate instance tags from an event window**  
Use the [Unregister-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Unregister-EC2InstanceEventWindow.html) cmdlet.

```
$tag1 = @{Key="key1"; Value="value1"}
$tag2 = @{Key="key2"; Value="value2"}
Unregister-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -AssociationTarget_InstanceTag @($tag1, $tag2)
```

**To disassociate instance IDs from an event window**  
Use the [Unregister-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Unregister-EC2InstanceEventWindow.html) cmdlet.

```
Unregister-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -AssociationTarget_InstanceId i-1234567890abcdef0, i-0598c7d356eba48d7
```

**To disassociate a Dedicated Host from an event window**  
Use the [Unregister-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Unregister-EC2InstanceEventWindow.html) cmdlet.

```
Unregister-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -AssociationTarget_DedicatedHostId h-029fa35a02b99801d
```

------

## Modify an event window
<a name="modify-event-windows"></a>

You can modify all of the fields of an event window except its ID. For example, when daylight savings begin, you might want to modify the event window schedule. For existing event windows, you might want to add or remove targets.

You can modify either a time range or a cron expression when modifying the event window, but not both.

------
#### [ Console ]

**To modify an event window**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation pane, choose **Events**.

1. Choose **Actions**, **Manage event windows**.

1. Select the event window to modify, and then choose **Actions**, **Modify instance event window**.

1. Modify the fields in the event window, and then choose **Modify event window**.

------
#### [ AWS CLI ]

**To modify the time range of an event window**  
Use the [modify-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/modify-instance-event-window.html) command.

```
aws ec2 modify-instance-event-window 
    --instance-event-window-id iew-0abcdef1234567890 \
    --time-range StartWeekDay=monday,StartHour=2,EndWeekDay=wednesday,EndHour=8
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "TimeRanges": [
            {
                "StartWeekDay": "monday",
                "StartHour": 2,
                "EndWeekDay": "wednesday",
                "EndHour": 8
            }
        ],
        "Name": "myEventWindowName",
        "AssociationTarget": {
            "InstanceIds": [
                "i-0abcdef1234567890",
                "i-0be35f9acb8ba01f0"
            ],
            "Tags": [],
            "DedicatedHostIds": []
        },
        "State": "creating",
        "Tags": [
            {
                "Key": "K1",
                "Value": "V1"
            }
        ]
    }
}
```

**To modify a set of time ranges for an event window**  
Use the [modify-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/modify-instance-event-window.html) command.

```
aws ec2 modify-instance-event-window 
    --instance-event-window-id iew-0abcdef1234567890 \
    --time-range '[{"StartWeekDay": "monday", "StartHour": 2, "EndWeekDay": "wednesday", "EndHour": 8},
	  {"StartWeekDay": "thursday", "StartHour": 2, "EndWeekDay": "friday", "EndHour": 8}]'
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "TimeRanges": [
            {
                "StartWeekDay": "monday",
                "StartHour": 2,
                "EndWeekDay": "wednesday",
                "EndHour": 8
            },
            {
                "StartWeekDay": "thursday",
                "StartHour": 2,
                "EndWeekDay": "friday",
                "EndHour": 8
            }
        ],
        "Name": "myEventWindowName",
        "AssociationTarget": {
            "InstanceIds": [
                "i-0abcdef1234567890",
                "i-0be35f9acb8ba01f0"
            ],
            "Tags": [],
            "DedicatedHostIds": []
        },
        "State": "creating",
        "Tags": [
            {
                "Key": "K1",
                "Value": "V1"
            }
        ]
    }
}
```

**To modify the cron expression of an event window**  
Use the [modify-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/modify-instance-event-window.html) command.

```
aws ec2 modify-instance-event-window 
    --instance-event-window-id iew-0abcdef1234567890 \
    --cron-expression "* 21-23 * * 2,3"
```

The following is example output.

```
{
    "InstanceEventWindow": {
        "InstanceEventWindowId": "iew-0abcdef1234567890",
        "Name": "myEventWindowName",
        "CronExpression": "* 21-23 * * 2,3",
        "AssociationTarget": {
            "InstanceIds": [
                "i-0abcdef1234567890",
                "i-0be35f9acb8ba01f0"
            ],
            "Tags": [],
            "DedicatedHostIds": []
        },
        "State": "creating",
        "Tags": [
            {
                "Key": "K1",
                "Value": "V1"
            }
        ]
    }
}
```

------
#### [ PowerShell ]

**To modify the time range of an event window**  
Use the [Edit-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Edit-EC2InstanceEventWindow.html) cmdlet.

```
$timeRange1 = New-Object Amazon.EC2.Model.InstanceEventWindowTimeRangeRequest
$timeRange1.StartWeekDay = "monday"
$timeRange1.EndWeekDay = "wednesday"
$timeRange1.StartHour = 2
$timeRange1.EndHour = 8
$timeRange2 = New-Object Amazon.EC2.Model.InstanceEventWindowTimeRangeRequest
$timeRange2.StartWeekDay = "thursday"
$timeRange2.EndWeekDay = "friday"
$timeRange2.StartHour = 1
$timeRange2.EndHour = 6
Edit-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -TimeRange @($timeRange1, $timeRange2)
```

**To modify the cron expression of an event window**  
Use the [Edit-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Edit-EC2InstanceEventWindow.html) cmdlet.

```
Edit-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -CronExpression "* 21-23 * * 2,3"
```

------

## Delete an event window
<a name="delete-event-windows"></a>

You can delete one event window at a time.

------
#### [ Console ]

**To delete an event window**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation pane, choose **Events**.

1. Choose **Actions**, **Manage event windows**.

1. Select the event window to delete, and then choose **Actions**, **Delete instance event window**.

1. When prompted, enter **delete**, and then choose **Delete**.

------
#### [ AWS CLI ]

**To delete an event window**  
Use the [delete-instance-event-window](https://docs.aws.amazon.com/cli/latest/reference/ec2/delete-instance-event-window.html) command and specify the event window to delete.

```
aws ec2 delete-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890
```

**To force-delete an event window**  
Use the `--force-delete` parameter if the event window is currently associated with targets.

```
aws ec2 delete-instance-event-window \
    --instance-event-window-id iew-0abcdef1234567890 \
    --force-delete
```

------
#### [ PowerShell ]

**To delete an event window**  
Use the [Remove-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Remove-EC2InstanceEventWindow.html) cmdlet.

```
Remove-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890
```

**To force-delete an event window**  
Use the [Remove-EC2InstanceEventWindow](https://docs.aws.amazon.com/powershell/latest/reference/items/Remove-EC2InstanceEventWindow.html) cmdlet.

```
Remove-EC2InstanceEventWindow `
    -InstanceEventWindowId iew-0abcdef1234567890 `
    -ForceDelete $true
```

------