Click the Out Of Office tab, and in the Date & Time Conditions - One-off section, click + Add date range. Set a date range by clicking the date fields and then selecting a start and end date from the calendars. Set a start/finish time for the dates by clicking the time fields and then dragging the sliders horizontally to select the Hour and Minute. If you want your autoresponse to look like a human response, you can tell eDesk to delay sending this template for x minutes. Pro-tip: You can use this to prevent Amazon from detecting your message as an auto-response. Set Frequency if you want to prevent eDesk from auto-responding with the same template to every message about the same ticket. For OOO templates, it is common practice to select Autoreply every single incoming message but you can also select a frequency, for example, once every 6 hours. If you want to tell eDesk NOT to auto-respond with this template to messages from certain email addresses, enter them into the Exclude field, for example, [email protected], [email protected]. You can also exclude all email addresses from a certain domain by entering *@domain.com, for example, *@xsellco.com Tick this if you want to include the signature for the channel in the template.
For those of you arguing that entrepreneurs and salespeople must always be available, I present to you Exhibit A. While this is specific to Yesware (and you should check out their other OOO examples), it's easy enough to tweak to fit your industry.

Email is one of the top tools for business communication. People expect swift responses to their requests. If this expectation will not be met because you are away from your desk, your client or colleague needs to know.
I received one from a coworker in middle management that said something to the effect of “I’m working on a large-scale project and will be unable to answer email until X date. Please contact [direct report’s email] with any questions.” This went on for well over a month.