I have been reviewing your post to help find an Outlook solution. Unfortunatlly, even if you created a rule that will receive the message and forwarded or send using a specified template reply, the rule has no options to only send during a certain time frame.

As a work around i would suggest creating a server side rule that can be enabled during the time you need it and disabling it when you don't. I understand this is tedious, but i was unable to locate a specific Outlook add on tool to accomplish your request.

Best Reagrds,