Writing an effective out-of-office message is a key part of running any business. Although it may seem so simple, an incomplete or unclear out-of-office message will cause problems before you leave as well as when you return.
As with all winter breaks, but especially in a longer break, division and department leaders are responsible for ensuring that external contacts are aware of the closures and as appropriate salaried staff are performing services as necessary to meet the needs of the community during the closure, including checking email/voicemail and responding to time-sensitive matters.

I don’t include this much detail on my OOO, but I do include if I am out of the office for religious observance, because I don’t use electronics on my holidays and want people to know that I really won’t get their message until the holiday is over. (Unlike the norm in my workplace that otherwise senior people are checking email even if we’re sick or on vacation. I know, I know.)
This is how my voicemails to my doctor’s office, my son’s doctor’s office, his daycare, etc. all go. Actually, the few times I leave voicemails beyond that, this is how they go.