Overview
You are looking to set custom autoresponders based on timeframe i.e. one for normal working hours and a different one for after-hours.
Solution
The functionality to set up autoresponders to be triggered based on time of day is currently not supported.
You can only set up Auto Responders on an email queue as described in Setting up Autoresponders for Different Email Queues but you have no control over what time frame the autoresponder is triggered.
If you wish to have a custom autoresponder message for customers who open tickets after your normal working hours, a useful workaround is to incorporate the after-hours message in the same arintro phrase you have set up for normal working hours as this is triggered each time a ticket is opened, regardless of the time of day.
In addition to the article shared above, check out the following articles for more information on configuring autoresponders: