Verb
(idiomatic) To acknowledge someone; to give someone respect or attention; to tip one's hat
If you're lucky, she might give you the time of day.
(idiomatic, in the negative) To not acknowledge someone; to snub someone; to disrespect someone; to ignore someone
He won't give the time of day to someone like you or me.
I tried to say "hi", but she wouldn't give me the time of day.
(literally, dated) To tell someone the time of day by looking at one's wristwatch, etc.
Source: en.wiktionary.org