The calendar may say today is May 5, but many Americans know it as Cinco de Mayo -- a day of celebration of Mexican heritage and pride.

The holiday has been growing in popularity in the U.S., with restaurants and shops offering specials, bars and clubs selling cheap margaritas and some schools celebrating Mexican culture, with kids and teachers encouraged to don sombreros, sing traditional Mexican songs and bring in Mexican treats. Some have likened it to a Mexican St. Patrick's Day.

But what is it we're celebrating, exactly?

10 great Latin American restaurants on LIColumnSpicy Cinco de Mayo ice cream at LI shop10 fun cocktails for Cinco de Mayo

"El Día de la Batalla de Puebla" translates to "The Day of the Battle of Puebla," which took place during the French invasion of Mexico on this day in 1862. The greatly outnumbered Mexican army overcame the French attackers outside the city of Puebla (whose claim to fame includes the Poblano pepper and the world-famous Mole Poblano) and won the battle.

About a year later, the French withdrew. It's because of this that May 5 is often  misrepresented as Mexican Independence Day, but it isn't; that's actually "El Grito de Dolores," which is celebrated on the eve of Sept. 16.

Contrary to what some believe, the holiday was not brought to the U.S. by Mexican immigrants. In the book, "El Cinco de Mayo: An American Tradition," author David E. Hayes-Bautista explains the holiday is an American one, started in the 1920s by California Latinos and spreading across the country in the 1960s and 70s, "a period of tremendous transformation for Latinos in California."

advertisement | advertise on newsday

In essence, Cinco de Mayo is a celebration of American-Mexican culture and prominence in America. Hayes-Bautista has written he is dismayed by the blatant commercialization of the day, which has at times devolved into a day of stereotype perpetuation, drunken debauchery and what some have called "Drinko de Mayo."

In Mexico, meanwhile, Cinco de Mayo is not an official holiday, and Poblanos along with the rest of Mexicans are amused and bemused as to the turn the date has taken north of the border.