The festival of Muharram has significant religious importance for Muslims, beginning with the first day, which is known as the Islamic New Year. Each year, the holiday falls on a different day because the Islamic calendar is and 11 or 12 days shorter than the solar calendar used in Western countries.

This year, the new year falls on Oct. 13. Muharram is one of the four holy months of Islam and unlawful acts, such as fighting and bloodshed, are forbidden. In fact, the term "Muharram" translates to "forbidden."

"The Muslim New Year is really celebrated as a cultural holiday, not a particularly religious one," Imam Johari Abdul-Malik, director of outreach at the Dar al-Hijrah Islamic Center in Falls Church, Virginia, told the Washington Times.

The holiday has different significance for both Shiite and Sunni Muslims.

Muharram is a solemn holiday for Shiite Muslims, and they mourn on the first 10 days. During this time, they don black attire and participate in mourning gatherings. They visit mosques and shrines with their relatives to remember the matyr Imam Hussain, the Prophet Muhammad's grandson, who was killed in the Battle of Karbala in A.D. 680 on the 1oth day. This day is referred to as the day of Ashura. 

GettyImages-458376684 Pakistani Shiite Muslim devotees beat their chests during a religious procession marking Ashura in Karachi, November 2014. Ashura mourns the death of Imam Hussein, a grandson of the Prophet Muhammad, who was killed by armies of the Yazid near Karbala in A.D. 680. Photo: Getty Images

But for Sunni Muslims, the 10th day recalls when Moses led the ancient Israelites out of Egypt. The Prophet Muhammad fasted on this day because Moses did to celebrate Allah saving his people.

Muslims believe that other important events happened during the month of Muharram. It is said that Earth and heaven were created during this month. 

“In the Islamic calendar, it is also what began ‘hijra,’ " Abdul-Malik said, “the migration of the prophet and his companions to establish a place where they were free to practice their religion, and practice it with other people who would be free to practice their religion.”