Days of Religious Observance

Religious holidays and festivals vary in the timing of their observance. Jewish holidays start at sundown the day before the first full day of the holiday and end at sundown on the last day of the holiday. For example, the Jewish holiday of Passover is April 3, 2007, although the holiday begins at sundown on April 2 and continues for eight days.

Baha’i and Pagan/Wiccan holidays also begin at sunset the day preceding the holiday.

Islamic festivals begin at the first sighting of the moon on the evening before the first day of the holiday. For example, the holy month of Ramadan begins when the crescent moon is observed prior to the first day of the month of Ramadan, which is predicted to be September 13, 2007. Therefore, the beginning of Islamic festivals and events cannot be precisely predicted. Since the beginning of festivals and events depends on the actual observation of the moon, the exact beginning depends on climatic conditions, time zones, and other circumstances that affect the actual sighting of the moon. In this sense, the Islamic calendar is an observation-based calendar.

Coptic Orthodox Christians and most Eastern Orthodox Christians follow the Orthodox Old Calendar, or Julian calendar, in which fixed holidays currently fall thirteen days later than Western Christian holidays in the Gregorian calendar. For example, Christmas is celebrated on December 25 by Western Christians, while Orthodox Christians celebrate Christmas on January 7. Since the vernal equinox is used in calculating the date for Easter, the dates for Orthodox Easter and all related moveable holidays usually differ from those in the Western Christian Churches. Several Eastern Orthodox Churches, such as the Greek and Cypriot Orthodox Churches, follow the Orthodox New Calendar, in which the Gregorian calendar is used for fixed holidays such as Christmas, and the Julian calendar is used for calculating Easter and all related moveable feasts.

There are two different branches of Buddhism: Theravada, the only surviving school of the original sects of Buddhism and the predominant religion of continental Southeast Asia and Sri Lanka, also found in parts of Indonesia, Malaysia, and Vietnam; and Mahayana, the later revisionist school of Buddhism found primarily in China, Japan, and Korea, and parts of the Republic of China and Vietnam. Offshoots of the Mahayana tradition include Vajrayana, found in Tibet and Mongolia, Jodo (Pure Land), and Zen Buddhism. Buddhists who follow the Theravada tradition celebrate holidays according to the lunar calendar, in which dates of observance vary from year to year, while those who follow the Mahayana tradition celebrate holidays on fixed dates, based on the Japanese Buddhist calendar. In this calendar, Visakaha Day is observed in accordance with the Theravada school, while all other Buddhist holidays follow the Mahayana tradition.

Hinduism is one of the oldest of the world’s religions, having originated in what is now India in the second millennium B.C. It has an estimated 793 million followers worldwide, predominantly in India, Nepal, and Southeast Asia. Hinduism is a complex of polytheistic religion and philosophy that evolved from Vedism and seeks to help people move beyond human imperfection. The Hindu calendar is based on a year of 12 lunar months, with the
discrepancy between this lunar year and the solar year of 365 days resolved by adding an extra month every 30 months.

The Sikh community has traditionally followed the Hindu Bikarami calendar, a lunar calendar in which the dates of Sikh holidays move from year to year. Since the Bikarami calendar does not conform to the tropical year length, this continual shifting of dates has led to festivals being celebrated out of season. In order to remedy this discrepancy and also to give the Sikh community their own separate calendar, the Nanakshahi calendar was created, named after the founder of Sikhism, Guru Nanak. Introduced in 1999 and officially approved by the Sikh clergy in 2003, the Nanakshahi calendar converts all Gurupurabs, the festivals marking events in the lives of the Gurus, to fixed dates in the Gregorian solar calendar. All Sikh festivals are now celebrated on their Nanakshahi dates, with the exception of Hola Muhalla, Bandi Chhor Day, and Guru Nanak Ji’s Birthday, which are still celebrated according to the traditional Bikarami calendar.