Although the country's Communist leader, Fidel Castro, declared his government atheist soon after his Marxist guerrillas ousted Fulgencio Batista 40 years ago, he only abolished the paid Christmas holiday in 1969, because, he said, he needed everyone to work on the sugar harvest.
Under pressure from the Pope, who visited Havana in January, President Castro finally agreed to make Christmas a permanent public holiday. Cubans, most of whom are Catholic, rushed out to buy Christmas trees, decorations and religious icons. With an alacrity any capitalist country would have been proud of, state stores had all of the above in stock and were offering 30 per cent discounts to boost sales.
The strictest Muslim countries, such as Saudi Arabia, forbid public manifestations of Christmas, but for millions of Indian Christians the problem is Hindu fundamentalism.
This year, attacks on Christians by "Hindu Talibans" have escalated in number and ferocity and Christmas will be celebrated with caution.
The situation has been worst in Gujurat in the north-west, Mahatma Gandhi's state and the home of non-violence. But there have also been attacks in other states, even in Goa, where whitewashed Catholic churches are ubiquitous. Services have been disrupted, churches and chapels looted, priests beaten up, Bibles burned and nuns gang-raped.
The forces blamed most often are the thuggish foot-soldiers of militant Hinduism, who claim Christianity is an alien, Western imposition. Indian Christians point out that their religion has existed there since St Thomas arrived on the Kerala coast in 52AD.
In much of the world, 25 December is just another working day. In Japan fewer than one per cent of the population are Christian and the traditional time for exchanging gifts is New Year. The (apocryphal) story which best illustrates the Japanese people's confusion about Christmas concerns a Tokyo department store which went to great efforts to put up a lavish festive display. There was a huge tree decorated with lights, thickets of holly and ivy, and piped muzak carols. And at the centre stood a huge Father Christmas, with red coat and beaming smile - securely nailed to a large wooden crucifix. Mysteriously, Christmas eve has become a second St Valentine's day in Japan, with restaur-ants and the ubiquitous "love hotels" which let rooms by the hour booked up weeks in advance.
China also goes to work on Christmas day, but is moving further from the Maoist days when Christmas was banned. Now Christmas is a new, glorious marketing opportunity, at least if there are foreigners in sight. This year, cages even appeared outside Peking's state-owned Friendship Store offering live turkey, goose, pigeon and guinea fowl.
In Macau, celebrating its last Christmas under Portuguese rule, things will be only slightly different. Despite the best efforts of the Portuguese over more than four centuries, only 6 per cent of the population adopted Catholicism. While the administration will shut down for the best part of a week, commercial activity will continue as usual.
Closer to home, Germany and Italy are in the grip of Christmas-related scares. The discovery of high concentrations of a toxic weedkiller in Christmas trees has panicked Germans. Even life-long Greens are considering going plastic.
And this year Italians may eat several million fewer panettoni, the bell-shaped, fruit-filled Christmas cake, following a campaign by animal rights activists, who claim to have poisoned the traditional Italian sweet. As a result, cassata from Sicily and Neapolitan struffoli are enjoying a revival.
Late shoppers would have little chance of finding a butcher's shop open on Friday in Britain, but in Paris, in the morning at least, there will be butchers open on every shopping street - along with bakers, greengrocers and markets. French shopping and eating habits may be changing, but enough people demand freshly bought food to make it worthwhile for specialist shops to open for a few hours on Christmas day.
In Spain, it is traditional to receive a "Christmas basket" - a box of wine, whisky, sugared almonds and slabs of nutty turron - from your employer. If your bosses are generous you might find a whole cured ham, some cheeses and tins of mussels and pate. The custom was introduced by Franco, who sought to prevent an impoverished nation from going hungry over the holidays - and muffle troublesome wage demands.
In the southern hemisphere, Christmas is, of course, celebrated in the middle of summer. At Sydney's Bondi Beach, the authorities are anxiously preparing for the traditional invasion of British and other backpackers on Christmas day, who will enjoy the novelty of plum pudding and champagne by the surf.
After past clashes involving drunken revellers and high-spirited local lads, the authorities are erecting an enclosure on the beach to confine the expats, with alcohol allowed inside it but banned outside.
At Australia's other geographical extreme, Father Christmas, aka Jim Hayes, will arrive by helicopter in Alice Springs, in forecast 40C temperatures, to deliver presents to 200 children from outlying farms, some of whom will have travelled up to 400 miles.
You might expect a concession to Christmas lunch in such heat: salad and fruit? "No, we saddle up to a traditional hot turkey dinner out here. Goodness knows why. But it wouldn't be Christmas without it."
Reported by Phil Davison in Miami, Peter Popham in Delhi, Richard Lloyd Parry in Tokyo, Teresa Poole in Peking, Stephen Vines in Hong Kong, Imre Karacs in Bonn, Frances Kennedy in Rome, John Lichfield in Paris, Elizabeth Nash in Madrid and Robert Milliken in Sydney.