Rabbi Philip R. Alstat, an early leader of Conservative Judaism, known for his fiery rhetoric and powerful oratory skills, wrote and spoke in 1939 about the power of the Passover story during the rise of Nazi persecution and terror:
In Israel, Passover is the seven-day holiday of the Feast of Unleavened Bread, with the first and last days celebrated as legal holidays and as holy days involving holiday meals, special prayer services, and abstention from work; the intervening days are known as Chol HaMoed ("Weekdays [of] the Festival"). Jews outside the Land of Israel celebrate the festival for eight days. Reform and Reconstructionist Jews usually celebrate the holiday over seven days. Karaites and Samaritans use different versions of the Jewish calendar, which are often out of sync with the modern Jewish calendar by one or two days. In 2009, for example, Nisan 15 on the Jewish calendar used by Rabbinic Judaism corresponds to April 9. On the calendars used by Karaites and Samaritans, Abib or Aviv 15 (as opposed to 'Nisan') corresponds to April 11 in 2009. The Karaite and Samaritan Passovers are each one day long, followed by the six-day Festival of Unleavened Bread – for a total of seven days.
The Passover begins on the 15th day of the month of Nisan, which typically falls in March or April of the Gregorian calendar. The 15th day begins in the evening, after the 14th day, and the seder meal is eaten that evening. Passover is a spring festival, so the 15th day of Nisan typically begins on the night of a full moon after the northern vernal equinox. However, due to leap months falling after the vernal equinox, Passover sometimes starts on the second full moon after vernal equinox, as in 2016.