In Jewish tradition, each 24-hour period begins at sunset, hence the morning is really the middle of the day. Thus Shabbat begins in the evening, as do all the festivals. This order curiously sets us apart from non-Jewish dating systems and could be considered a defining feature of the Jewish calendar (https://www.jpost.com/jewish-world/judaism/world-of-the-sages-day-or-night-when-do-we-start#:~:text=5%3A5).-,In%20Jewish%20tradition%2C%20each%2024%2Dhour%20period%20begins%20at%20sunset,feature%20of%20the%20Jewish%20calendar)