The novel has been called the literary sensation of the decade, having sold more than a million copies. The film, starring Anne Hathaway and Jim Sturgess, is certain to become a hit when it comes out on Friday. But can David Nicholls' One Day, the love story that everyone is raving about, now stake a claim on the city of Edinburgh? One canny tourist board seems to think so.
Marketing Edinburgh last week launched a literary tour of the Scottish capital, a six-mile walk taking in all the sites mentioned in the book. Never mind that Edinburgh already boasts a dozen festivals, three castles and a literary heritage stretching from Walter Scott to Harry Potter – now tourists can flock to see where Emma and Dexter fall in love. Well, that's what I did.
"Begin in the heart of the Old Town," say the instructions, sending me to the jostling market square of Grassmarket; there a man juggles chainsaws next to an African dance troupe. No mention of this in the novel, but this is festival season.
In case you haven't read it, One Day is about the romance between Emma Morley and Dexter Mayhew, who meet as students at Edinburgh University. Their paths cross the day they graduate, 15 July 1988, and the novel traces their lives every year on that date for two decades.
So, to get in the mood, I pop into Armstrongs, the vintage clothing store, where the manager, Jane Barrow, tells me she's doing a booming trade in Eighties clothes. "Wing-sleeve jumpers are the thing," she says, showing me a hideous, baggy, black number with bits of gold appliqué.
On to George IV Bridge, where it's thick with tourists, so I dive into the National Library of Scotland, where Emma might have studied. Dera Bell, 32, has lived here for 10 years, and says Edinburgh is just like Paris – "a good place to forge relationships".
Round the corner is Parliament Square, where Ems and Dex would have attended their graduation ceremony and first clapped eyes on one another. Today, it's throbbing with rucksacked tourists; tour guide Ella Humphreys, 24, rolls a cigarette as she waits for her next group. Has she ever fallen in love in this square? "I've fallen in and out of love a couple of times in Edinburgh," she laughs, "so, yeah, I can see how it might happen."
On Cockburn Street, where several scenes were filmed, I find some actual lovers. Dylan Kitchener, 26, and Joanna Blusiewicz, 30, are sitting arm-in-arm, drinking lager outside The Malt Shovel pub. She is Polish, he Australian, and they have just moved to Edinburgh. But as for finding romance here, they're not convinced. "It's not Paris," they scoff.
There's certainly no Doisneau-style kissing going on in Princes Street Garden, as trains chunter through Waverley station. Maria Thorburn, 46, is sitting on a bench. "At dusk, it's very romantic here," she says, gazing towards the castle's craggy outcrop. And, like in One Day, she has found romance here. "My partner is younger – he's 33," she laughs. "It took me a long time to find love, but I have."
A light drizzle falls as I cross bus-choked Princes Street into New Town, the most intact area of Georgian architecture in the world. Forres Street, just off the magnificent Moray Place, is where Hathaway and Sturgess kiss in the film's poster. Stair-rods of rain are turning the façades a darker shade of slate, and nobody seems to be doing any kissing. I look for a suitable candidate, and find a woman who asks not to be named. We don't kiss, but she says she has often kissed in the street.
Down the hill is Fettes Row, where Dexter lived; three estate agents' boards tantalisingly suggest his flat might be to let. Jill Pollock stops to talk, and soon we are swapping ghost stories. I head up to Calton Hill, the park with superb views and an ideal location for a romantic stroll, but there are few couples here today.
I reach the final stop, Rankeillor Street, where the novel begins, in Emma's single bed. Barry Cormack, 62, has lived here 30 years and is one of the few locals who isn't a student.
"I've seen them all come and go," he sighs. "Ballet dancers, nurses, actors, all traipsing up and down the stairs." But does he know which one was Emma's flat, I ask?
He points to a green door and turns away. I ring the bell. No answer. The shutters are half-closed, and a school desk stands rotting in the courtyard. Upstairs, a supermarket trolley is visible through a window. I ring again and, as I wait, I try to imagine Anne Hathaway living here. Nobody appears. Not today then. But one day.