One Day is simply the tale of Emma Morley and Dexter Mayhew, their short-lived graduation fling and the following two decades of their lives.
But the intriguing concept, whereby the reader gets to check in with them, sometimes together, more often apart, on the 1st July each year, has caught the imagination of millions of readers. It became the UK's best-selling book of 2010 and has been translated into more than 30 languages across the world.
Next month sees the story brought to the screen, with American star stepping into the role of Emma, the serious-minded heroine set against the more effortlessly charming Dex, played by British up-comer Jim Sturgess.
Devotees of the book will no doubt be casting a critical eye over Hathaway's performance - taking on an English-accented role and a very popular part - while Hathaway herself claims to understand the magic of the book and why readers hold it so dear:
"I will always remember the experience of reading the book," she recalls. "It was like it was on fire, it was lit from within."
Hathaway has form for the accent, winning praise for her clipped tones as Jane Austen in 2007's Becoming Jane, while One Day author David Nicholls, surely the hadest person to please, has no doubt the right woman has been cast:
"I think Anne has the intelligence and the wit and the warmth that Emma needs, it's been really thrilling to see the book and the script come to life, it's a really faithful adaptation"
Fans will be able to decide for themselves next month, when One Day goes on release on 26th August.
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