In order to ban Group Member for a certain period of time :
- Click on Members Tab
- Hover/Click on User Options
- Click on the Ban Button
- Under take action Select Temporary Ban
- Enter the Ban Till Time
- Click on Take Action
Alternative Method :
You can even ban the Group Member directly from chat area :
- Hover/Click on User Message
- Click on the User (with lock) Icon
- Under take action Select Temporary Ban
- Enter the Ban Till Time
- Click on Take Action