Create an e-mail Out of Office Reply option when creating an appointment or meeting in your calendar.
When creating an appointment or meeting in your calendar you should be able to create an auto reply (out of Office) associated with that calendar event. That way if you have multiple periods that you will be out of the office you can have it set up without having to remember just prior to the appointment.
Jonathan Simmons commented
I've just been looking for this exact thing, having had to work odd shifts (different each day) with my wife, sharing childcare, etc… People keep forgetting when I am working (and when I'm not) so having this would be extremely helpful! Also useful for leave, etc... Don't understand why there are not more votes for this - it would be revolutionary!
Neah Jackson commented
I would vote for hits over and over again. I am so bad at remembering to set my out of office but also don't want people to think I am ignoring emails when I am actually away in meetings.