when does shabbat start

Shabbat officially starts at sunset on Friday, not when it gets dark or cloudy. Traditionally, candles are lit 18 minutes before sunset to provide a grace period ensuring no one begins Shabbat later than the actual sunset. This candle lighting time marks the beginning of Shabbat. The time of sunset, and thus when Shabbat starts, depends on the location and time of year but always begins at sundown Friday and lasts until sundown Saturday, lasting 25 hours.