G2250

ἡμέρα

hēmera

Feminine noun · From (with ὥρα (G5610) implied) of a derivative of hemai (to sit, akin to the base of ἑδραῖος (G1476)) meaning tame, i.e. gentle

Feminine (with G5610 implied) of a derivative of ἧμαι hēmai (to sit; akin to the base of G1476) meaning tame, i.e. gentle; day, i.e. (literally) the time space between dawn and dark, or the whole 24 hours (but several days were usually reckoned by the Jews as inclusive of the parts of both extremes); figuratively, a period (always defined more or less clearly by the context):—age, + alway, (mid-)day (by day, (-ly)), + for ever, judgment, (day) time, while, years.

Outline

the day, used of the natural day, or the interval between sunrise and sunset, as distinguished from and contrasted with the night

in the daytime
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

of the civil day, or the space of twenty four hours (thus including the night)

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.

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
used of time in general, i.e. the days of his life.