On what date does Yom Kippur fall?

Yom Kippur, the Day of Atonement, is the 10th of Tishrei. The Torah places its observance from evening to evening (Leviticus 23:27–32): it begins on the evening before the 10th, not on the following morning. Eating must stop before sunset so that some weekday time is added to the holy day (Shulchan Aruch, OC 608:1). At its conclusion, one waits beyond nightfall to add time again (OC 624:2); use a reliable local timetable.

The restrictions apply at night as well as by day: eating and drinking, washing, anointing, wearing leather footwear, and marital relations are prohibited (OC 611:1). Work prohibited on Shabbat is also prohibited on Yom Kippur (OC 611:2). These basic laws are shared by Ashkenazi and Sephardi communities.

Medical safety is not a secondary consideration. If a competent doctor says fasting may make an illness dangerous, the person is fed according to the circumstances described in OC 618:1. Arrange guidance before the fast when possible; this page cannot determine an individual medical exemption.

A Beit Din may ask whether fasting alone repairs wrongdoing against another person. It does not: reconciliation is required for such offences (OC 606:1). A common mistake is focusing only on enduring hunger while neglecting an apology or restitution. Yom Kippur concerns repentance, not an endurance contest.