NET
31 Therefore be alert, remembering that night and day for three years I did not stop warning each one of you with tears.
Darby
31 Wherefore watch, remembering that for three years, night and day, I ceased not admonishing each one [of you] with tears.
KJV
31 Therefore watch, and remember, that by the space of three years I ceased not to warn every one night and day with tears.