The reason for our joy is the holiday of Purim, celebrated on the fourteenth. Actually, though, there is another reason that this month is doubled. Adar comes right before Nisan, the month when Passover is celebrated. The most important reason for the leap year is so that Passover will always be celebrated in the Spring. Therefore, the extra month is added at this season, to make sure that Passover will come at the right time.
Tonight is the twentieth day of the month.
However, we did not celebrate Purim last week, on the fourteenth. Usually, when we have the choice to do something either sooner or later, our Jewish tradition teaches us to advance occasions of joy. And yet, the observance of Purim in a leap year is an exception. Purim must always be observed one month before Passover, as the two holidays are linked in a spring festival season. Mordecai Kaplan, one of the greatest rabbis of the twentieth century, taught that American Jews should participate fully in two cultures, American and Jewish.