Yusnier Viera mathematician who can calculate what day any date fell on

January 29, 2024

Yusnier is one of the best calculators of all time. He was born in Bejucal, in the current Cuban province of Mayabeque, and holds 21 world records because he can calculate in fractions of a second what day any date fell on.

Described on more than one occasion as "the human almanac" and based since 2007 in Miami, United States, Viera is recognized for repeatedly breaking the global record in calendar dates.

In October 2023, it marked 18 years since someone told him that he would not be able to break a Guinness World Record in mental mathematics, but "I didn't listen to the skeptics and proved to them that they were wrong."

According to what the 41-year-old Cuban expressed when recalling the date, a graduate in Computer Science from the University of Havana, "the power of the mind is unlimited" so "we are all capable of achieving incredible things if we set our minds to it."

When he was 35 years old, he calculated the day of 140 dates from five centuries in one minute, which got him into the Guinness Book of World Records, as he has done multiple times since 2005, when he obtained his first world record in the Cuban capital.

Although that first record was with 42 dates, almost a hundred fewer than the new record he set 13 years later, for him it was the most significant of his career because it made him the first person in the American continent to crown himself in date calculation.

Obsessed with dates since he was in university, he studied eight hours straight daily because he wanted to compete in the World Mathematics Olympiad.

He created his own mathematical algorithm to calculate the days because "in the early 2000s, access to the internet in Cuba was almost zero" and he did not have the possibility to research "how other people made these calculations." This way, the operations became increasingly easier for him and his method was increasingly effective, he told BBC Mundo.

Viera narrated that the first time he left Cuba, for the World Olympiad in Germany, whose organizers covered his travel expenses, he knew he could continue being the best in the world at date calculation and that he no longer wanted to continue living on the island.

In 2007, during a Mathematics championship in the city of Puebla, Mexico, the Caribbean native defected and entered the United States through the southern border.

In 2010 he achieved one of his most praiseworthy records: calculating 20 dates from the present century, that is, between the years 2000 and 2999, in just over eight seconds, a mark that no one has surpassed since then.

He attended as a guest on the Fox network's Superhumans program in 2016 and later on the popular The Ellen DeGeneres Show, where he was able to demonstrate his impressive abilities.

In 2018 he told BBC that "to set a record perhaps you do need to have a talent, but calculating dates quickly just takes a lot of practice and a good algorithm."

"It's not about being the best," but about "believing in yourself and never giving up on your dreams," he said recently on Facebook with the idea of inspiring those who follow him to pursue their passions, "no matter how impossible they may seem."

"Don't let anyone tell you what you can or cannot achieve. Be your own record breaker! Let's turn our dreams into reality, break barriers and set our own records," he added in his motivational message.

Viera, who does not forget that what he is today "I have to thank" the education he had in Cuba, is the author of the books Basic Course of Mental Arithmetic and Master the Multiplication Tables.

This week he announced his incorporation into the team of the Cuban Professional Baseball Federation, better known as FEBCUBE, to support it through sabermetrics, an empirical analysis of baseball that is based on statistics collected during games and whose name comes from the acronym of the Society for American Baseball Research (SABR).

A very curious fact about the famous mathematician, which he revealed to BBC, is that, since the mind is selective, it can "do a calculation very quickly for you or tell you when a date is going to fall," but "I almost never remember where I left my car keys."