1
general::
Phrase(s): night and day
Go to day and night.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Also day and night. Continually, without stopping. This phrase is used either literally, as in The alarm is on night and day, or hyperbolically, as in We were working day and night on these drawings. Shakespeare put it by night and day in The Comedy of Errors (4:2): "Time comes stealing on by night and day."
American Heritage Idioms