Man, having grown tired of ageing past 25, has been altered to remain forever young. Finding no sport in such an existence, clock implants have been invented which kill the implantee if he does not have Time. Time, which may be earned and spent like conventional money, or alternatively stored and stacked like gold in Time-Bricks, is also necessary in order to live. Time may be transferred by touch without authorization, which is not an issue. The rich live apart from the poor in bordered "Time-Zones", which may just be normal, bordered time-zones.
Our hero, J-Time (Justin Timberlake), works in a Time-Brick factory making Time-Bricks. He lives with girlfriend mother in the fashionable Dayton ghetto, and enjoys spending time/Time at the local bar, wherehe saves a wealthy man of 105 from a gang. Grateful, the elderly man teaches J-Time about inflation and gifts J-Time his Time, killing himself. The large transfer causes suspicion with Leon (Cillian Murphy), a Timekeeper (an officer of the time).
A surprise increase in the cost of public transportation kills J-Time's mother, causing him to travel to New Greenwich in order to seek revenge on no-one in particular. Eventually he ends up at a casino, where he wins a game of Texas Hold'em against Weiss (Pete Campbell from Mad Men), a Time banker; additionally, he wins the heart of Weiss' daughter (Amanda Seyfried), figuratively. Leon seizes J-Time's Time save two hours, causing him to take Amanda hostage.
After this point, the two become time bandits, stealing Time from banks to distribute to the poor, without much by way of plot; Weiss is robbed and Leon runs out of Time. At the end of the film, the two Time bandits plan to knock off a massive bank.