1
general::
A day away from work, school, or a similar obligation; a free day. For example, Sophie always used her day off to do errands. [Late 1800s]
American Heritage Idioms
2
general::
Phrase(s): *the day off
a day free from working. (*Typically: get ~; have ~; give someone ~; take ~.) • The next time I get a day off, we’ll go to the zoo. • I have the day off. Let’s go hiking.
McGrawhill's American Idioms And Phrasal Verbs