Happy Holidays is used only around Christmas in the USA. Traditionally, it was meant to include both Christmas and New Year's Day. We don't usually say "Happy Holiday" at other times, although there's nothing wrong with saying it.
Whatever you decide before heading out for that much-needed time off, it’s imperative that you set up an out of office reply. Your customers and co-workers don’t get that same pause button as you do. That’s why you should inform everyone that needs to know about your time off.

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.
I set mine for long meetings (half a day or a whole day) or if I’m traveling. I do have clients who email about time sensitive issues and it’s better for everyone if they know I might not see their message for a few hours.