The Epiphany is the twelfth day after Christmas (January 5th) and is the day that the magi arrived to greet Jesus. The Epiphany is not a significant holiday in American Tradition, but countries like Mexico treat it as a day even bigger then Christmas itself.
On the night of the Epiphany, the children in Mexico treat the wise men arriving as we treat Santa in America. They fill shoes up with foods for the wise men's camels and leave them outside of their doors. In the morning there are gifts waiting for them where they left the shoes.
On the Epiphany, Mexico's major cities have huge parades and many festivities are set up all around to commemorate the importance of the day.
Although the holiday is of great significance in Mexico, the government does not recognize it as a national holiday. Therefore, markets and government offices are open for business.
It is a tradition to eat Rosco de Reyes on the Epiphany in Mexico, which is a sweet bread with a figurine of baby Jesus inside.
In very religious families, the person who finds the Jesus figurine in his or her bread becomes known as "Jesus's godparent".
References: https://www.timeanddate.com/holidays/mexico/holy-kings. http://www.latintimes.com/what-dia-de-los-reyes-6-facts-about-three-wise-men-day-latin-america-36182