According to the Qur'an, Allah created the universe with an exact number of days, months, and years so mankind might be able to calculate time conveniently. However, because the Muslim calendar is totally lunar, and is not adjusted to the sun, it moves backwards through the years, making a complete retrograde cycle about once every thirty-two and a half years. . . . The Islamic New Year is a religious event, occurring on the first day of the first lunar month, Muharram, with prayers for peace and prosperity, but its secular traditions include the exchange of good wishes and coins, which are supposed to bring good luck.