What is Cinco de Mayo?
Cinco de Mayo is 5 May, the anniversary of Mexico's victory over invading French forces at the Battle of Puebla in 1862. It is often mistaken for Mexican independence day, which is 16 September. In Mexico the observance is largely regional and centred on Puebla; in the United States it has grown into a much larger celebration of Mexican-American culture. The date is fixed, so the countdown rolls to the following year once 5 May has gone by.
In Puebla the day is marked with a parade and a re-enactment of the battle, and across Mexico it is a civic commemoration rather than a day off, so most of the country works. North of the border the concentration of events makes it one of the busier nights of the year for bars and restaurants, and the week before is when the bookings and the supply orders go in. Because the date is fixed, a Cinco de Mayo on a Friday or Saturday behaves very differently from one in the middle of the week. Confusion with Mexican independence, celebrated on the night of 15 September and the day of the 16th, is common enough that event listings sometimes carry the wrong symbols. The victory at Puebla did not end the French intervention, which continued for years afterwards.
Puebla state keeps the date as a local holiday, and the civic programme centres on the hills above the city where the forts stood. In the rest of Mexico it is a school commemoration rather than a day away from work. Elsewhere in Latin America, and in Spain, it passes without notice at all. The rule people get wrong is the Monday one: Mexico moved several of its civic dates onto fixed Mondays so they would produce long weekends, and this is not among them, because it is not a statutory holiday to begin with and so has nothing to move.
The next one falls on Wednesday, 5 May 2027, and this page counts down to the midnight that starts it in whatever time zone your browser reports.