Saint Patrick's Day is the most international of national days, celebrated from Boston to Buenos Aires and from Singapore to Seoul. What those cities also tend to share each March 17 are the mild warm conditions perfect for throwing a street party.
In Ireland it's different. There's an old saying that March comes in like a lion, and the Irish winter normally lurks in the long grass to give us a good mauling at the first glimpse of a skimpily dressed majorette.
But does St Patrick's Day have to be on March 17? Couldn't we move it to sometime more kindly?
That's just what we did 10 years ago in 2001 when foot and mouth brought Ireland to a standstill. March was scratched, and when the Dublin parade belatedly took place on a beautiful late May day it drew the biggest turnout ever of some 1.2 million.
In theory, Paddy's Day could be moved. After all, the Catholic Church shunts it whenever it interrupts Easter Week. In 1940, for instance, the Church observed it on April 3 and in 2008 on March 14.
Legend has it that St Patrick died on March 17, 461, but it's really a case of 'pick a number, any number'. It was given a slot on the calendar of saint's days in the 1600s after lobbying by the Waterford-born missionary Luke Wadding.
In practice, St Patrick's Day can't be moved because it's become such a world fixture that it's no longer ours. We share it with many parts where snow, rain and hail will never be a case for change.
In some places, we share it in a most literal sense. March 17 is a public holiday on the Caribbean island of Monserrat because it commemorates a failed slave revolt in 1768, which, by coincidence, ties in with the celebrations of the many islanders of Irish stock. In Boston, the feast doubles up with the original public holiday of Evacuation Day marking the withdrawal of British troops during the 1776 revolution.
Such ambiguity is typical of the legacy of Patrick, a man who might have been born in Wales or Scotland or elsewhere, and whose real name might have been Maewyn Succat.
That said, from our own bitter experience we must concede that he might indeed have frozen to death under a barrage of hailstones on March 17, 461.
Here's 17 things we do know, sort of, about St Patrick's Day.
1 This State's first St Patrick's Parade took place in Dublin in 1931. New York lays claim to the world's first planned parade in 1762, but Boston claims an inpromptu one for 1737 when a meeting of the new Charitable Irish Society spilled on to the streets and turned into a procession of rowdy paddywhackery.
2 St Patrick's association with green is just a couple of centuries old. For over 1,000 years St Patrick's hue was blue and today St Patrick's Blue is the official colour of the President, the National Stud and UCD's sports teams. Before partition, the strip of the Irish national football squad was St Patrick's Blue.
3 St Patrick's Day did not become a public holiday here until 1903 when the Westminster Parliament passed a bill introduced by the Irish MP James O'Mara. Twenty years later, O'Mara would do his best to ruin the day for millions. (See No 5)
4Before independence, the puritanical Gaelic League waged a campaign of moral intimidation against publicans, demanding they shut their doors all day Paddy's Day. The bullying worked for a few years until the publicans, realising there was no law to force them to close, defied the republicans.
5 With Independence in 1922, the new political elite made a ban on Paddy's Day pub opening a top priority. James O'Mara led the way as chief killjoy. In support, one TD said "the drowning of the shamrock" was "a direct insult to the Saint" that must be "obliterated".
A senator insisted that if St Patrick came back to life he'd drown anyone drowning the shamrock. Countess Markievicz stressed that in addition to pubs, hotels must also stay dry because "I do not see why rich people should not be kept off their drink as well as poor".
6 In Australia, Melbourne's city fathers also tried to stamp out Paddy's Day drinking in 1922, but from a different angle. The pro-British officials opposed Irish independence. Cork-born Archbishop Kevin Mannix led a campaign of civil disobedience and the parade passed off. At the next Irish general election a woman stormed out of the polling station shouting that if she couldn't vote for Archbishop Mannix she'd vote for no one.
7 The pub ban became law in 1927, but TDs worried about sales from the head shops of the day, so-called 'dairy shops' with names like Hyacinth, Bluebell and Tulips. These were openly selling wine on Paddy's Day, as were the country's chemists. One TD worried about women getting a prescription filled and slipping a sly bottle of port into their handbags.
8 Guinness gave most workers the day off. With no pubs open, the lucky ones were those who had to work the holiday. They received triple pay and as much stout as they could guzzle.
9 For decades, all adverts were banned on St Patrick's Day, which was devoted to traditional music, religious services and uplifting back-from-the-future speeches such as Taoiseach De Valera's 1943 pep-talk looking forward to returning to a Brigadoon world of "happy maidens dancing at the crossroads".
10 From 1927 to 1961 the RDS Dog Show was the only place to legally drink on Paddy's Day. Huge crowds turned up. One TD complained it was a grand occasion "except for all the damned dogs".
11 The independent republic of Limerick openly flouted the opening ban, with thousands of drinkers flooding the lawless city. Limerick police gave the publicans the 'Nelson's Eye', after the admiral who ignored orders by turning his blind eye to semaphore signals.
12 Nelson's Pillar on Dublin's O'Connell St was half demolished by a terrorist bomb a week before Paddy's Day 1966. The Army blew up the stump two days before the parade, causing far more damage than the bombers. RTÉ and the newspapers obeyed a government request to censor out the wreckage from parade coverage.
13 In a Simpson's Paddy's Day special, newsman Kent Brockman calls it "the day when everyone is Irish, except the gays and the Italians". The NY parade's ban on gays remains upheld in law because it's deemed a religious event.
14 There was a diplomatic incident in Rome in 1969 when Italian VIPs received invites to a Paddy's Day bash at the Irish embassy. The bigwigs were miffed that unused invites from 1968 had been recycled, with the '68 date crossed out and '69 inserted.
15 This year's Moscow parade has been abandoned on the grounds it would cause traffic disruption. Some believe the real reason is Ireland's recent expulsion of a Russian spymaster for forging Irish passports. A miniature indoor party will replace the parade.
16 As Tourism Minister in 1996, Enda Kenny oversaw the extension of Dublin's St Patrick's Day parade into a week-long festival. At the other end of the scale is the Cork village of Dripsey which stages the world's shortest parade, which runs 23.4 metres from The Weigh Inn pub to The Lee Valley bar, which bookend the hamlet.
17 St Patrick's Day 1959 saw the birth of the least successful ever Irish export to the US. The brainchild of Irish-American businessman William Curtis, The Shamrock was a gas-guzzling saloon. Sadly, the engine was far too puny to carry the big, heavy frame, and it was impossible to change a punctured tyre without dislocating the entire axle. Ten thousand were supposed to flood the US market. Eight were completed before the kitty ran out.