What is Shavuot? The Jewish festival that started hours after Boulder, Colorado, attack

Sunday afternoon’s attack in Boulder, Colorado, took place hours before the start of a major Jewish festival, Shavuot.

Authorities say a man used a flamethrower and threw an incendiary device into a group holding one of its regular rallies in solidarity with Israeli hostages in Gaza. Eight people were injured, some with burns.

Shavuot (pronounced Shah-voo-OTE), Hebrew for "weeks,” has been observed since biblical times. It marks the passing of seven weeks (49 days) from the holiday of Passover, with Shavuot falling on the 50th day.

In biblical times, Shavuot was an agricultural festival, when Israelites would bring harvest offerings to the temple.

Today, it’s primarily commemorated as the traditional date on which God gave the Torah - the law that forms the heart of the Jewish Scriptures - to Moses on Mount Sinai, as described in the Bible.

The 50-day time period gives the festival its Greek name, Pentecost, which is also the name for a holy day on the Christian calendar.

Shavuot falls on the 6th of Sivan on the Jewish calendar, which reckons days as beginning at sundown. This year, Shavuot began Sunday evening and continues for one or two days, depending on tradition.

For Jews inside Israel and for Reform Jews, the festival lasts for one day. Other traditions outside of Israel observe Shavuot for two days, ending Tuesday evening this year. (The variation stems from different traditions on when to observe lunar holidays, which historically were based on moon observations in ancient Israel.)

Shavuot typically falls in May or June on the Gregorian calendar.

Jews celebrate with readings of the biblical book of Exodus, including the Ten Commandments. Some mark the occasion with all-night readings from the Torah and other religious texts. Observant Jews refrain from work on Shavuot. The biblical book of Ruth, about a woman who embraces the Jewish faith, is often read and studied.

Shavuot celebrations are often marked by the consumption of dairy products, such as cheesecake and cheese-filled blintzes. Explanations for this tradition vary; one is that the Torah is like nourishing milk for the spirit.

Reform Judaism has traditionally connected Shavuot to its rite of confirmation for teens, in which they affirmed their commitment to Jewish life.

Tragically, this year’s Shavuot is not the first time in recent memory that Jews have marked a normally festive holiday in grim circumstances.

Hamas’ Oct. 7, 2023, attack on Israel, claiming about 1,200 lives, took place on Simchat Torah, a date when Jews celebrate the completion of their year-long cycle of Torah readings.

Sunday's gathering in Boulder was to raise attention for the 58 hostages, around a third believed to be alive, who are still being held by Hamas.