These mostly religious festivals and other traditions have been maintain despite the urbanization of the borough. The calendar of celebrations here is extensive. Some are civic or political events such as Independence Day or local celebrations such as the birth of poet Fernando Celada, the birth of Quirino Mendoza y Cortés, composer of “Cielito Lindo,” and the commemoration of the meeting of Francisco Villa and Emiliano Zapata on December 4 in this area. However, most events are tied to religious activity and tradition, organized by volunteers called mayordomos. The mayordomia system is the most important social structure in the borough. The primary task of these volunteers is to sponsor and organized any many religious festivals and celebrations that occur through the year, as well as other duties. This may be paid for by collecting donations or paid for directly by the mayordomo. There are 422 officially recognized festivals during the year, including those local to specific communities. One of these more localized festivals is on May 3, Day of the Holy Cross, which has been celebrated in communities such as Santa Cruz Xochitepec (or Magdalena Xochitepec), Santa Cruz Acalpixcan and the center of Xochimilco for over 400 years.