Q: Passage: It is traditionally eaten on January 6, during the celebration of the Dia de Reyes (literally "Kings' Day"), which commemorates the arrival of the three Magi or Wise Men. In most of Spain, Spanish America, and sometimes, Hispanic communities in the United States, this is the day when children traditionally get presents, which are attributed to the Three Wise Men (and not Santa Claus or Father Christmas). In Spain before children go to bed, they leave a dish filled with biscuits and a few glasses of water for the three wise men and the camels they ride on. The baby Jesus hidden in the bread represents the flight of the Holy Family, fleeing from King Herod's Massacre of the Innocents. Whoever finds the baby Jesus figurine is blessed and must take the figurine to the nearest church on February 2 (Candlemas Day, Dia de la Candelaria). In the Mexican culture, this person has the responsibility of hosting a dinner and providing tamales and atole to the guests. In U.S. communities with large Mexican and Mexican-American populations, such as Los Angeles, San Diego, San Jose, Dallas and Chicago, the celebration includes the Mexican hominy stew pozole, which is made for all one's neighbors.

Question: Based on this passage, when do you buy a rosca de reyes?
Let's give stream of consciousness below
The relevant information is: It is traditionally eaten on January 6, during the celebration of the Dia de Reyes (literally "Kings' Day"), which commemorates the arrival of the three Magi or Wise Men. So the answer is January 6 , during the celebration of the Dia de Reyes ( literally '' Kings ' Day '' ).