How does shabbat begin?

Answer:
God sanctified the Sabbath (Genesis 2:1-4). It begins either through our initiative or by default.
Through initiative, if one accepts the Sabbath early, such as when women light the candles before sundown, or the men say the Lecha Dodi prayer before sundown.
By default, the Sabbath begins at sundown on Friday in any case, such as if one was sleeping.
First answer by Galileedawn. Last edit by Galileedawn. Contributor trust: 29 [recommend contributor recommended]. Question popularity: 1 [recommend question].