You might not always be present to answer incoming chats. To inform your customers when you are not available to answer a chat, you can set your opening hours.
When you add an Out of Office notification, your customers know what they can expect from you. Customers expect your respond quickly, when you are not around, you can send automatic notifications. Those will only be sent once you receive messages outside your opening hours. You need to do this per communication channel.
We advise you to add the out of office replies when you will be back in the office to pick up the support need. When other communication channels are supported 24/7, we suggest to add how those can be used to get support. Email addresses, phone numbers, and or a link to frequently asked questions or your website might also be helpful.