1) the day, used of the natural day, or the interval between
    sunrise and sunset, as distinguished from and contrasted with
    the night
    1a) in the daytime
    1b) metaph., "the day" is regarded as the time for abstaining from
        indulgence, vice, crime, because acts of the sort are
        perpetrated at night and in darkness
 2) of the civil day, or the space of twenty four hours (thus
    including the night)
    2a) Eastern usage of this term differs from our western usage. Any
        part of a day is counted as a whole day, hence the expression
        "three days and three nights" does not mean literally three
        whole days, but at least one whole day plus part of two other
        days.
 3) of the last day of this present age, the day Christ will
    return from heaven, raise the dead, hold the final judgment,
    and perfect his kingdom
 4) used of time in general, i.e. the days of his life.