Set your status:

1. Click your person icon in the top right corner of your Teams window.

2. From the menu, select the status drop-down arrow below your name and email address.

3. Select your desired status from the list.

Reset your status:

1. Click your person icon in the top right corner of your Teams window.

2. From the menu, select the status drop-down arrow below your name and email address.

3. Click Reset status.

Set your status/duration:

1. Click your person icon in the top right corner of your Teams window.

2. From the menu, select the status drop-down arrow below your name and email address.

3. Click Duration.

4. Click the drop-down menu to set your Status.

5. Click the drop-down menu to Reset status after and select the duration of time you wish your status to be set.

6. To set a Custom duration, select Custom from the drop-down menu.

7. Enter the date and time you wish your status to reset and click Done.

For more information on Changing your status in Teams, please review this article from Microsoft.