SHORTLY after he turns 21 years old, nice guy Tim (Domhnall Gleeson) learns from his father (Bill Nighy) that he harks from a long line of male time travellers, who can go back along their own timeline to correct past mistakes and relive fond memories.
Slowly, Tim masters his new skill, which comes in very handy when he crosses paths with an insecure beauty called Mary (Rachel McAdams) and bungles their first meeting.
With the benefit of time travel, Tim corrects wrinkles in the relationship and romance blossoms. However, every correction risks ripples through time and Tim gradually learns there are some imperfections which must never be smoothed.
"All the time travel in the world can't make someone love you," Tim's father reminds him tenderly.
Set largely in London with occasional forays to the picturesque Cornish coast, About Time is a bittersweet rom-com about saying goodbye to the people you love and bidding farewell to childhood and the safety net of a parent's guiding hand.
This is purportedly Richard Curtis's final film in the director's chair and it is a fittingly amusing and heartbreaking swansong.
Cast in the everyman role usually reserved for Hugh Grant, Gleeson is a loveable hero and catalyses wonderful screen chemistry with McAdams and Nighy.
Laughter abounds, tempered by the poignancy of sequences between Tim and his father.
Admittedly, Curtis is guilty of old habits. Characters are almost exclusively white, upper middle class, and seem to be able to afford sizeable properties despite modest salaries.
But once you accept realism is a distant stranger to certain elements of the writing, About Time casts a heady spell.