One example of the influence the spanish conquistador's religion had on day of the dead are the

dates the holiday is celebrated on.

Explanation:

Day of the Dead was originally an indigenous, specifically Aztec celebration that started in the later summer and went on to early fall. It was not really a centralized holiday, but rather a series of celebrations during a specific seasons involving ideas about the cycle of life and death and death's importance to life.

When the Spanish conquistadors arrived in the 16th century, they brought with them their religion in the form of Catholicism. Catholicism, being monotheistic, was in stark contrast to the polytheistic religion of the indigenous peoples of Mexico. The Spanish conquistadors, although they tried to convert the indigenous to their own religion and largely succeeded over time, did not force the polytheists to follow Spanish tradition for everything. In many ways, the conquistadors allowed for cultural mixing to occur.

One of these ways was in making the Day of the Dead celebration align with All Saint's Day in the Catholic calendar, which takes place on November 1. In Mexico, people believe that this is the day that spirits come back from the dead to roam the Earth. In celebration of this belief, Mexicans set out alters for their deceased loved ones to usher them back to the land of the living. It is worth mentioning that All Saint's Day is a Catholic Church holiday dedicated to celebrating, as the name indicates, all saints.

This holiday alignment between pagan and Christian celebrations is typical in other countries around the world. Christmas (winter solstice) and Easter (spring equinox) are two similar examples.