First Monday in February – Constitution Day (Día de la Constitución)  
On the first Monday in February the Mexican flag is flown at full staff in accordance with the Law on the National Arms, Flag, and Anthem (Ley sobre el Escudo, Bandera y el Himno Nacionales) in commemoration of both the Mexican constitution which was adopted on February 5, 1917 and the former constitution which was adopted on February 5, 1857.  

Prior to 2006 Constitution Day (Día de la Constitución) was celebrated on February 5th.  Thereafter, to create a three day weekend, it has been celebrated on the first Monday in February.  

Constitution Day (Día de la Constitución) is a Mexican federal statutory holiday.  Employees are entitled to a day off with pay plus overtime pay if they are required to work on the holiday.  Banks, many businesses, government offices, and schools close for the holiday.

The current constitution, adopted in 1917, limits a president to a single six year term; it also forbids members of the military from being elected president.  This has prevented the dictatorships (by both civilians and military generals) that were part of Mexico’s history prior to the Mexican Revolution that began 1910.

 
The 1917 Constitution  
The current Mexican Constitution was drafted in Santiago de Querétaro by a Constitutional Convention during the Mexican Revolution.  It was approved by the Mexican Constitutional Congress on February 5, 1917, with Venustiano Carranza serving as the first president under its terms.  It is usually recognized with the festivals and street celebrations.  

The Mexican Revolution that began in 1910 brought about social and cultural changes which mark the beginning of modern Mexico.  The revolution started as a rebellion against President Porfirio Díaz, an accomplished general and the President of Mexico continuously from 1876 to 1911, with the exception of a brief term in 1876 when he left Juan N. Mendez as interim president, and a four-year term served by his political ally Manual Gonzalez from 1880 to 1884.  

Díaz is commonly considered by historians to have been a dictator and is a controversial figure in Mexican history.  The period of his leadership was marked by significant internal stability (known as the "paz porfiriana"), modernization, and economic growth.  However, Díaz's conservative regime grew unpopular due to repression and the failure of the poor to improve their economic conditions.  The years in which Díaz ruled Mexico are referred to as the Porfiriato.

As the gulf between the poor and rich grew wider under Díaz, and the political clout of the lower classes also declined.  Díaz was once quoted as saying of his own people, “The Mexican people would amount to nothing without being driven by the whip.”  The opposition of Díaz surfaced when Francisco I. Madero, who was educated in Europe and at the University of California, began to gain recognition and political power.

Díaz had Madero imprisoned, feeling that the people of Mexico weren't ready for democracy.  During this time, several other Mexican folk heroes began to emerge, including the well known Pancho Villa in the north, and the peasant Emiliano Zapata in the south.

Díaz was unable to control the spread of the growing insurgence and resigned in May, 1911, with the signing of the Treaty of Ciudad Juárez, after which he fled to France (dying a few years later).  Madero was then elected president, but was opposed by Emiliano Zapata who did not wish to wait for an orderly implementation of Madero’s desired land reforms.  Zapata denounced Madero as president and took the position for himself.  Zapata controlled the state of Morelos, where he chased out the estate owners and divided their lands to the peasants.  Later, in 1919, Zapata was assassinated by Jesus Guajardo acting under orders from General Pablo Gonzalez.

Emiliano Zapata was born in 1879 in the Mexican state of Morelos, the son of a farmer.  He proved to be a natural born leader and his destiny soon revealed itself.  His father died when he was 17 and shortly thereafter, Emiliano assumed the responsibility of providing for his family.  Zapata was of Mestizo blood and he spoke Nahuatl, the indigenous language of central Mexico. Widely respected by his community, the village elected Zapata to be their leader in 1909. He quickly recruited an insurgent army of farmers from his village to protect the farms in their immediate community.  Zapata and his men fought the government troops in the south of Mexico while Pancho Villa fought in the north.

Pancho Villa was born Doroteo Arangol in Durango on June 5, 1878, the son of a field laborer.  As an adolescent Villa became a fugitive after killing a man who assaulted his sister.  Fleeing to the mountains, he changed his name and became a bandit.  In 1910 he joined the rebellion led by Francisco Madero, which was successful.  When Madero was assassinated in 1913 Villa formed an army several thousand strong which came to be known as the Division del Norte - the Division of the North.  He fought on the side of Venustiano Carranza and the Constitutionalists.

Eventually, Venustiano Carranza became president and organized a convention that produced the Constitution of 1917, which is still in effect today.  Carranza made land reform an important part of that constitution.  This resulted in the ejido, or farm cooperative program, that redistributed much of the country's land from the wealthy land holders to the peasants. The ejidos are still in place today and comprise nearly half of all the farmland in Mexico.

 
The 1857 Constitution
Constitution Day also honors the 1857 constitution.  The 1857 constitution, like the 1917 constitution, was adopted on a February 5th.

The 1857 constitution was a liberal constitution drafted by 1857 Constituent Congress of Mexico during the presidency of Ignacio Comonfort giving birth to the Second Federal Republic of Mexico. It was ratified on February 5, 1857, establishing individual rights such as freedom of speech; freedom of conscience; freedom of the press; freedom of assembly; and the right to bear arms. It also reaffirmed the abolition of slavery, eliminated debtor prison, and eliminated all forms of cruel and unusual punishment, including the death penalty.

Some articles were contrary to the interests of the Catholic Church, such as education free of dogma, the removal of institutional fueros (privileges) and the sale of property belonging to the church. The Conservative Party strongly opposed the enactment of the new constitution and this polarized Mexican society. The Reform War began as a result, and the struggles between liberals and conservatives were intensified with the implementation of the Second Mexican Empire under the support of the church. Years later, with the restored republic, the Constitution was in force throughout the country until 1917.

The War of Reform was a Mexican civil war fought from December 1857 to January 1861, launched by liberal and moderate revolutionists dissatisfied with the Catholic Church’s stranglehold on governmental affairs. The war ended with victory for the liberals and President Benito Juárez brought his administration to Mexico City.  

Because of the War of the Reform, the 1857 Constitution remained without effect in almost all of Mexico until January, 1861, when the Liberals returned to the capital.  On 1862, as a result of Franco-Mexican War and the establishment of Second Mexican Empire, the Constitution was again suspended.  On 1867 the government of Juarez overthrew the Empire, restored the Republic, and the Constitution again took effect in the country.

The 1857 Constitution remained in force until the adoption of the 1917 Constitution.  In some ways the 1917 Constitution furthered the spirit of the 1857 Constitution.