Tonight is Yom HaShoah, the day of commemoration for our murdered millions, for the few but shining examples of those who had the chance to rebel and fight back, and for the unfathomable courage of those who simply survived and rebuilt their lives.

Why do we mark it on this date on the Jewish calendar, the 27th of Nissan? (As the 27th falls on Friday this year, the marking of the day was moved up, per longstanding tradition, so that Israeli public ceremonies won’t interfere with Sabbath observances.)