Yom Kippur is the holiest day of the Jewish calendar. The English translation means “Day of Atonement.”
It’s the day where Jews attend (long) services and ask for forgiveness for sins and forgive others.
It’s a solemn period for self-reflection, and ideally, personal improvement in the new Jewish year.
In addition, able-bodied congregants abstain from food or drink for a period of 24 hours. If you need more instruction, I highly recommend checking the biblical book Leviticus for more details.
This year, Yom Kippur starts on the evening of Friday September 29th and ends on sundown on Saturday September 30th.