Cuban President Raul Castro turns 81 on Sunday, another year on in his race against time to reform Cuba's economy and try to assure the survival of communism after he and his elderly colleagues are gone.
Their task, he has said, is to correct mistakes made during their 53 years of leadership, which will require "days and years of work" that he intends to finish.
"The generation that made the (Cuban) revolution has had the historic privilege, few times seen, of being able to direct the rectification of errors they themselves committed," he told a Communist Party conference in January. "Despite the fact that we are not so young, we don't plan to waste this last opportunity."
Raul Castro's No. 2, Jose Ramon Machado Ventura is 81 and his No. 3, Ramiro Valdes is 80.
Older brother Fidel Castro, who led Cuba for 49 years before age and infirmity forced him to leave office, is 85 and still a behind-the-scenes player.
The average life expectancy for a Cuban male is about 76 years.
President Castro has said his health is good and he feels young, plus there is a history of longevity in his family. His sister Angela died in February at the age of 88 and his eldest brother Ramon is 87.
If he is worried about time, Raul Castro does not let on publicly.
He has fretted publicly about not having groomed younger leaders to succeed the current group, but there are no obvious candidates waiting the wings.
He has said on several occasions that the remaking of Cuba's economy will be done "without hurry, but without pause" so that the mistakes of the past are not compounded by more mistakes.
Many people think he needs to move faster, regardless of his age.
Since officially succeeding older brother Fidel Castro in 2008, he has launched reforms to encourage private initiative and reduce the role of the state, which controls 90 percent of the economy.
He has put more agriculture in private hands, opened the doors for small private businesses and begun giving state companies more autonomy. He wants to cut a million jobs, or about 20 percent of the workforce, from the government's payrolls.
He has allowed Cubans to buy and sell cars and homes, privileges denied to them for five decades.
But there are questions about whether President Castro is doing enough to modernize the struggling Soviet-style economy and accomplish his goal of saving the communist system put in place after the 1959 revolution.
The Communist Party affirmed at a congress in 2011 that central economic planning would continue and the accumulation of property not allowed.
Many people think Cuba needs to open up its economy in the style of fellow communist-led countries China and Vietnam.
"The challenge for Raul Castro and the leadership of the Communist Party continues to be the orderly implementation of a transition to a mixed economy and a society open and integrated to the world," said Cuba expert Arturo Lopez-Levy at the University of Denver.
Serious problems loom that may force deeper and faster change on Cuban leaders.
The economy is swimming in debt, sources of foreign income are limited - partly due to the longstanding U.S. trade embargo against Cuba - and the island is heavily dependent on Venezuelan President Hugo Chavez for oil and investment.
Chavez, 57, is battling cancer and facing re-election in October. His death or political demise could end Venezuela's special relationship with Cuba, which would deal a serious economic blow to the island.