All Jewish religious festivals and holidays (like Shabbat) are 25 hours long, starting at nightfall and ending the following nightfall. Dates are fixed according to the ancient Jewish calendar, and may fall on a different date every year. Muslim, Christian and other religious holidays are also observed by the respective populations.

Purim
March
A day of fancy dress and a mini-carnival.
Throughout the city

Pesach (Passover)
Usually April
Starts with ‘Seder Night' - a festive ritual meal on the first evening. Nothing which is ‘leavened' is allowed all week including bread and beer. First and last days are holidays.
Throughout the city

Israel Independence Day
Usually May
Celebrations of the declaration of the State of Israel in 1948 with concerts and picnics.
Throughout the city

Tel Aviv Pride
June
Israel's biggest, loudest, most ostentatious gay celebrations.
Throughout the city

Jaffa Nights
August
Annual four-day street festival of music, theatre, dance and art exhibitions.
Old Jaffa

Rosh Hashanah (Jewish New Year)
September-October
Two-day family celebrations.

Sukkot (Feast of Tabernacles)
September-October
For a week colourful little shelters and 'booths' are erected everywhere to echo the refuges sought by Jews in the dessert after the exodus from Egypt. Starts two weeks after Rosh Hashanah.
Throughout the city

Chanukah (Festival of Lights)
December
In homes, workplaces, and in the street, hanukkiot candelabras are lit in the evening with one extra candle each night for a week, throughout the city.

Note: *Only the first and last days of Passover and Sukkot are national holidays, but there may be some disruption on intermediate dates; many shops and businesses may open but close early. The festival of Chanukah is a holiday period, but it is not a national holiday - businesses remain open.