Question: When do you buy a rosca de reyes?

Disambiguated questions and answers:
context: No context provided
question: When and for what do you buy a rosca de reyes?
short_answers: Día de Reyes

to celebrate Epiphany

Kings' Day

context: It is traditionally eaten on January 6, during the celebration of the " ("Kings' Day"), which commemorates the arrival of the three Magi or Wise Men. In most of Spain, Latin America, and their Diaspora throughout the world, this is the day when children traditionally get presents, which are attributed to the Three Wise Men (as opposed to Santa Claus). 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.
question: When do you buy and eat a rosca de reyes?
short_answers: January 6
wikipage: Rosca de reyes

context: No context provided
question: During what celebration do you buy a rosca de reyes?
short_answers: Epiphany

context: No context provided
question: On what date do you buy a rosca de reyes?
short_answers: January 6

Long answers:
knowledge: content: The roscón de reyes is celebrated in Spain and other Hispanic countries, such as Mexico. Recipes vary from country to country and between cultures but tend to be similar.
wikipage: King cake Spanish-speaking countries

content: In Argentina, Paraguay, and Uruguay, and Mexico City, the day is called "Día de Reyes" (The Day of Kings, a reference to the Biblical Magi), commemorating the arrival of the Magi to confirm Jesus as son of God. The night of January 5 into the morning of January 6 is known as "Noche de Reyes" (The Night of Kings) and children leave their shoes by the door, along with grass and water for the camel, horse and elephant.
wikipage: Epiphany (holiday) Argentina, Paraguay, and Uruguay

content: Roscón is a sweet bread-based ring-shaped dessert filled with guava paste. 
wikipage: Roscón
long_answer: The roscón de reyes is celebrated in Spain and other Hispanic countries, such as Mexico. Recipes vary from country to country and between cultures but tend to be similar. The sweet bread-based ring-shaped dessert is usually bought or baked during the Epiphany, or in Mexico City, "Día de Reyes", commemorating the arrival of the Magi to confirm Jesus as son of God. The night of January 5 into the morning of January 6 is known as "Noche de Reyes", or the Night of Kings, and children leave their shoes by the door, along with grass and water for the camel, horse and elephant.

knowledge: content: The roscón de reyes is celebrated in Spain and other Hispanic countries, such as Mexico.
wikipage: King cake Spanish-speaking countries

content: In Western Christian tradition, Epiphany (also known as "Three King's Day") celebrates the visit of the Magi to the Christ Child.[5]
wikipage: King cake History
long_answer: The roscón de reyes is celebrated in Spain and other Hispanic countries, such as Mexico. A rosca de reyes is traditionally eaten on January 6, during the celebration of the "Kings' Day", which commemorates the arrival of the three Magi or Wise Men. In Western Christian tradition, Epiphany (also known as "Three King's Day") celebrates the visit of the Magi to the Christ Child.