I used to work with someone who had a message telling people she only checked her email twice a day. You pretty much needed to call her if you needed anything outside of those times. (She worked in a remote office.) I think she had read one of those books on efficiency that recommended scheduled email time. But there were problems with this: 4. My department often had to email attachments or text to illustrate our questions/concerns. And we were on deadlines. Reading a page of text over the phone was not an efficient use of anyone’s time 5. She did outreach & was often out of the office on site visits, trainings, or travel to these places, but never ever set her OOO for these, because she was “working.” However, she was effectively not available to read emails from other staff until after hours on those days.
Carnegie Mellon's U.S. campuses observe 11 official holidays. The university is closed on these days, and all non-essential personnel are not expected to report to work. Regular, full-time staff members may also take up to three floating holidays per calendar year.

There’s a department at my workplace where this is common practice too. My old department worked with clients in similar ways, and I was half expecting we’d also be required to do it, but luckily that never happened. Further proof that, at this (generally progressive, flexible-working) company, your actual work-life balance heavily depends who manages you.
Setting your out of office may be different depending on the email provider you use. But whether you’re on Outlook, Gmail, or another platform, it should be a relatively straightforward process.