From Wikipedia, if you want a few facts about Day of the Dead:
Day of the Dead (Spanish: Día de los Muertos) is a Mexican holiday celebrated throughout Mexico and around the world in other cultures. The holiday focuses on gatherings of family and friends to pray for and remember friends and family members who have died. It is particularly celebrated in Mexico, where it is a national holiday, and all banks are closed. The celebration takes place on November 1, in connection with the Catholic holidays of All Saints' Day and All Souls' Day (November 2). Traditions connected with the holiday include building private altars honoring the deceased using sugar skulls, marigolds, and the favorite foods and beverages of the departed and visiting graves with these as gifts. They also leave possessions of the deceased.