This weekend, Orthodox Christians begin observing their Holy Week in preparation for Pascha, or Easter, on May 5. Because they follow a different calendar, Eastern Christians usually perform the series of traditional rituals leading up to Easter at a different time than Western Christians.

Members of the Baha’i faith celebrate the feast of Ridvan. The twelve-day holiday commemorates the Prophet Baha’u’llah’s announcement in 1863 that he was the new messenger of God.

Sikhs celebrate one of their most important holidays, Vaisakhi or Vesak. Often observed as a spring harvest festival, the day also marks the time when Sikhs first identified themselves as a defined group in the 17th century. Many Hindus observe Vaisakhi as a time of renewal and rebirth. Hindus are also celebrating the nine-day festival of Navaratri, which honors the many female forms of the deity, among them Durga and Shakti.

This weekend, April 7 is Holocaust Remembrance Day, Yom Hashoah. It is a solemn tribute to the six million Jews put to death by the Nazis during World War II.

Visit R & E’s extensive archive of stories and interviews done over the years on Yom HaShoah.

Hindus this week celebrate the colorful festival of Holi (March 27-28). During the popular celebration, families paint each other and toss colored water and powders that represent energy, life, and joy.

On Sunday (March 24), Western Christians observe Palm Sunday. It marks the beginning of Holy Week, days of prayers and services, among them Holy Thursday and Good Friday, all leading up to the celebration of Easter next Sunday (March 31).

This coming Monday night (March 25), Passover begins. Jews remember their ancestors’ deliverance from slavery in Egypt and their wandering for 40 years in the desert until finally they reached the Promised Land.

This weekend (March 11) Hindus celebrate Maha Sivaratri, which honors their deity Lord Shiva.

On March 2, Bahai’s begin a nineteen-day fast. They abstain from food and drink between sunrise and sunset and practice prayer and meditation. The time of fasting leads up to the New Year celebration, Nowruz.

This weekend (February 24) Jews celebrate Purim, when children join in the retelling of the story of Queen Esther and the Jews’ deliverance from a plot to destroy them. The long tale is called the megillah, from which any other long, complicated story has come to be called “the whole megillah.”

Western Christians will begin observing Lent, the 40-day period of prayer and fasting before Easter. The season begins with Ash Wednesday (February 13), when many receive an ash mark of penance on their foreheads.

Sunday (February 10) is Chinese New Year, when the Year of the Dragon ends, and the Year of the Snake begins. On New Year’s Eve, people will go to the temples and pray for good fortune for the new year.

The Jewish holiday of Tu B’Shevat began at sundown Friday (January 25). Called New Year’s Day for Trees, it has become a special day for efforts to protect the environment.

This weekend (January 19-20), some Eastern Orthodox Christians, including members of Coptic and Russian churches, celebrate Epiphany, the day they mark the baptism of Jesus.

The world’s largest religious festival got underway in India this week. Watch our report on the Hindu gathering Kumbh Mela.

Some Orthodox Christians celebrated Epiphany this week, a day on which they commemorate the Baptism of Jesus. As is traditional, in Istanbul, Greek Orthodox Christians jumped into the Bosphorus to retrieve a cross. Other Orthodox Christians, including the Russian and Coptic churches, will celebrate Epiphany on January 19.

Many Christians celebrate the Feast of the Epiphany on January 6. For Western Christians, the day marks the arrival of the Magi to visit the infant Jesus. Eastern Christians call it Theophany and commemorate the baptism of Jesus. For the Armenian Apostolic Church, which follows a different calendar, January 6 is the celebration of Christmas. Many other Eastern traditions, including the Russian Orthodox Church and the Coptic Church, celebrate the Feast of the Nativity on January 7.

Buddhists mark Bodhi Day (December 8), when they believe the Buddha attained enlightenment and reached a state of nirvana. According to tradition, he did so while sitting under a bodhi tree.

Hanukkah, the eight-day festival of lights, begins this weekend (December 8), when Jews light their Hanukkah lamp. The holiday recalls the victory of the Maccabean soldiers over the Assyrian-Greek King Antiochus.

Watch our interview about Hanukkah lamps and menorahs.

December 12 is the Feast Day of Our Lady of Guadeloupe. The day honors a vision of the Virgin Mary reported near Mexico City in the year 1531. Thousands of Catholics travel each year to the basilica built there in her name.

This weekend is World AIDS Day (December 1). Several faith groups are holding events to raise awareness of the disease and those suffering from it.

Also this weekend, the season of Advent begins on Sunday (December 2) for Western Christians and some branches of Eastern Orthodoxy. It’s a time of spiritual preparation for Christmas, and for many Christians it is also the beginning of the new church year.

And on Thursday, December 6, Christians celebrate the Feast Day of St. Nicholas, the patron saint of children, who many consider the inspiration for Santa Claus.

Many Muslims observe the solemn holiday of Ashura on November 24th. For Shiites, it commemorates the martyrdom of the Prophet Muhammad’s grandson during the Battle of Karbala.

This weekend (November 10) members of the Sikh faith celebrate the birthday of their founder, Guru Nanak.

Monday (November 11) Baha’is celebrate the birth of their founder, Baha’u’llah.

For Hindus, the five-day festival of Diwali, known as the Festival of Lights, begins Tuesday (November 12).

Also this week (November 15), Orthodox Christians begin observing Advent with the Nativity Fast, part of their spiritual preparation for Christmas.

And on Thursday (November 14) some Muslims will mark Al-Hijira, the Islamic New Year, which commemorates the migration of the Prophet Muhammad and his followers from Mecca to Medina in the year 622.

Many Christians this week observed All Saints Day (November 1), a time to remember saints and martyrs.

Watch our 2006 story on the annual observances of All Hallow’s Eve at the Dominican House of Studies in Washington. Friars there choose saints to honor out of the roughly 10,000 whom Catholics venerate, and the Dominicans’ vigil has become a big draw for priests, nuns, and especially college students.

Hindus celebrated Dussehra, marking the triumph of good over evil when Lord Rama defeated Ravana, who had abducted his wife.

This weekend (October 28), Protestants observe Reformation Sunday, recalling the day in 1517 when Martin Luther nailed his 95 theses to the church door in Wittenburg, Germany.

On November 1st, Christians celebrate All Saints Day, a time to honor saints and martyrs.

And November 2nd is All Souls Day celebrated by Catholics and some Protestants. During this time, many Latinos also observe what they call the Day of the Dead, when it’s believed the spirits of the departed return to Earth.

On Saturday (October 20), members of the Baha’i faith mark the birth of the Bab, who they believe was a messenger of God. He was born in 1819 in modern-day Iran.

Hindus continue to celebrate the nine-day festival of Navaratri, which began on Tuesday (October 16). It honors the goddess Shakti, the divine mother, and her different manifestations.

And for Muslims, the Hajj, or pilgrimage to Mecca, begins this coming week. All Muslims who are able to do it are called upon to participate at least once in their lifetime. Muslims will also observe Eid al Adha or the Feast of the Sacrifice. It’s a three-day period of prayer that commemorates the prophet Abraham’s willingness to sacrifice his son in obedience to God.