In countries which use the Gregorian calendar, New Year's Day is usually celebrated on 1 January. The order of months in the Roman calendar has been January to December since King Numa Pompilius in about 700 BC, according to Plutarch and Macrobius. However, Roman writers identified years by naming the year's consuls, who did not enter office on 1 January until 153 BC. Since then 1 January has been the first day of the year, except during the Middle Ages when several other days were the first (1 March, 25 March, Easter, 1 September, 25 December). With the expansion of Western culture to the rest of the world during the twentieth century, the 1 January date became global, even in countries with their own New Year celebrations on other days (e.g., China and India). At present, the celebration of the New Year is a major event worldwide. Many large-scale events are held in major cities around the world, with many large fireworks events on New Year's Eve (31 December). Sydney launched over 80,000 fireworks at midnight, and had more than one and a half million attendees; it was also the most-watched event on television worldwide last year. In Valparaiso upwards of two million visitors witnessed the largest fireworks display in a natural setting; a total of more than 21 kilometers of fireworks on the bay, from the commercial port city of Valparaiso to Concon, Chile, all in 25 minutes of entertainment. London's New Year celebrations centre around the London Eye, with an impressive fireworks display while Big Ben strikes midnight. In New York, the celebration is focused around a large crystal ball that descends in a one minute countdown in Times Square. Edinburgh plays host to one of the world's largest Hogmanay events. The celebrations last for four days and attract visitors from around the globe to take part in street parties and attend concerts. In the culture of Latin America there are a variety of traditions and superstitions surrounding these dates as omens for the coming year. January remains a symbol of the New Year's celebration. According to the Christian tradition, 1 January coincides with the circumcision of Christ (eight days after birth), when the name of Jesus was given to him (Luke 2: 21).

Martin Luther King, Jr. (January 15, 1929 – April 4, 1968) was an American clergyman, activist, and prominent leader in the African American civil rights movement. He is best known for being an iconic figure in the advancement of civil rights in the United States and around the world, using nonviolent methods following the teachings of Mahatma Gandhi. King is often presented as a heroic leader in the history of modern American liberalism. A Baptist minister, King became a civil rights activist early in his career. He led the 1955 Montgomery Bus Boycott and helped found the Southern Christian Leadership Conference in 1957, serving as its first president. King's efforts led to the 1963 March on Washington, where King delivered his "I Have a Dream" speech. There, he expanded American values to include the vision of a color blind society, and established his reputation as one of the greatest orators in American history. In 1964, King became the youngest person to receive the Nobel Peace Prize for his work to end racial segregation and racial discrimination through civil disobedience and other nonviolent means. By the time of his death in 1968, he had refocused his efforts on ending poverty and stopping the Vietnam War. King was assassinated on April 4, 1968, in Memphis, Tennessee. He was posthumously awarded the Presidential Medal of Freedom in 1977 and Congressional Gold Medal in 2004; Martin Luther King, Jr. Day was established as a U.S. national holiday in 1986.

Commemorates the births of George Washington (22.2.1732) and Abraham Lincoln (12.2.1809). The memory of America’s first president, George Washington, was once celebrated on his birthday, February 22nd. The date was changed to the third Monday in February to create a three-day weekend.

Memorial Day is a United States federal holiday observed on the last Monday of May (May 31 in 2010). Formerly known as Decoration Day, it commemorates U.S. soldiers who died while in the military service. First enacted to honor Union soldiers of the American Civil War – it was extended after World War I to honor Americans who have died in all wars. In the United States, Memorial Day marks the start of the summer vacation season, and Labor Day marks its end. Begun as a ritual of remembrance and reconciliation after the Civil War, by the early 20th century, Memorial Day was an occasion for more general expressions of memory, as ordinary people visited the graves of their deceased relatives, whether they had served in the military or not. It also became a long weekend increasingly devoted to shopping, family get-togethers, fireworks, trips to the beach, and national media events such as the Indianapolis 500 auto race, held since 1911 on Memorial Day.

Commemorates the formal adoption of the Declaration of Independence on July 4, 1776. The Fourth is traditionally celebrated publicly with parades and pageants, patriotic speeches, and organized firing of guns and cannons and displays of fireworks

International Workers' Day (a name used interchangeably with may day) is a celebration of the social and economic achievements of the international labor movement. May Day commonly sees organized street demonstrations and street marches by millions of working people and their labour unions throughout most of the countries of the world.

Many countries in the New World and elsewhere celebrate the anniversary of Christopher Columbus's arrival in the Americas, which occurred on October 12, 1492, as an official holiday. The event is celebrated as Columbus Day in the United States, as Día de la Raza in many countries in the Americas, as Discovery Day in the Bahamas, as Día de la Hispanidad and Fiesta Nacional in Spain and as Día de las Américas (Day of the Americas) in Uruguay. These holidays have been celebrated unofficially since the late 18th century, and officially in various countries since the early 20th century.

Veterans Day is an annual United States holiday honoring military veterans. A federal holiday, it is observed on November 11. It is also celebrated as Armistice Day or Remembrance Day in other parts of the world, falling on November 11, the anniversary of the signing of the Armistice that ended World War I. (Major hostilities of World War I were formally ended at the 11th hour of the 11th day of the 11th month of 1918 with the German signing of the Armistice.) The holiday is commonly printed as Veteran's Day or Veterans' Day in calendars and advertisements. While these spellings are grammatically acceptable, the United States government has declared that the attributive (no apostrophe) rather than the possessive case is the official spelling.

The date and location of the first Thanksgiving celebration is a topic of modest contention. The traditional "first Thanksgiving" is the celebration that occurred at the site of Plymouth Plantation, in 1621. According to tradition, the Pilgrims hosted a delegation of about 90 Wampanoag led by a chieftain Massasoit. The Wampanoag are but one of a multitude of distinctive nations that at that time were already living in areas subjected to colonization that eventually became the northeastern United States and southeastern Canada. Although organized violence, epidemics and rampant discrimination often characterized interactions between European colonists and peoples whose ancestors arrived thousands of years earlier, the peaceful harvest festival that became the Thanksgiving prototype created a more benevolent paradigm of possibilities for cooperation; however, these possibilities were often overlooked by both sides in following centuries until the closing of the frontier in 1890. The Plymouth celebration occurred early in the history of what would become one of the original thirteen colonies that became the United States. However, there was another, more modest Thanksgiving at Berkeley Plantation, Virginia on the banks of the James River in 1619. The celebration became an important part of the American myth by the 1800s. This Thanksgiving, modeled after celebrations that were commonplace in contemporary Europe, is generally regarded as America's first. Today, Thanksgiving is celebrated on the fourth Thursday of November in the United States and on the second Monday of October in Canada. Thanksgiving dinner is held on this day, usually as a gathering of family members and friends.

Christmas or Christmas Day is an annual Christian holiday commemorating the birth of Jesus Christ. It is celebrated on December 25, but this date is not known to be Jesus' actual birthday, and may have initially been chosen to correspond with either the day exactly nine months after some early Christians believed Jesus had been conceived, a historical Roman festival, or the date of the northern hemisphere's winter solstice. Christmas is central to the Christmas and holiday season, and in Christianity marks the beginning of the larger season of Christmastide, which lasts twelve days