'Night and Day' in the Bible

So ever be on your guard and always remember that for three years, night and day, I never ceased warning you one by one, and that with tears.

You remember, brothers, our hard labor and toil. We kept up our habit of working night and day, in order not to be a burden to any of you when we preached to you.

as night and day I continue to pray with deepest earnestness and keenest eagerness that I may see your faces and round out to completeness what is lacking in your faith?

I did not eat any man's bread without paying for it, but with toil and hard labor I worked night and day, in order not to be a burden to any of you.

But a woman who is really a widow and lives alone has fixed her hope on God, and night and day devotes herself to prayers and entreaties,

I thank God, whom I worship, as my forefathers did, with a clear conscience, as I ceaselessly remember you in my prayers. Because I remember the tears you shed for me, I am always longing night and day