Untimed (Rules of the Regulator, #1)

Charlie's the kind of boy that no one notices. Hell, his own mother can't remember his name. So when a mysterious clockwork man tries to kill him in modern day Philadelphia, and they tumble through a hole into 1725 London, Charlie realizes even the laws of time don't take him seriously. Still, this isn't all bad. Who needs school when you can learn about history first hand, like from Ben Franklin himself. And there's this girl... Yvaine... another time traveler. All good. Except for the rules: boys only travel into the past and girls only into the future. And the baggage: Yvaine's got a baby boy and more than her share of ex-boyfriends. Still, even if they screw up history - like accidentally let the founding father be killed - they can just time travel and fix it, right? But the future they return to is nothing like Charlie remembers. To set things right, he and his scrappy new girlfriend will have to race across the centuries, battling murderous machines from the future, jealous lovers, reluctant parents, and time itself.