When? Time tricks keep TV shows hopping

“You don't screw with time,” Mama Petrelli warned Peter – technically, Future Peter – in the season premiere of “Heroes.”

Peter didn't heed the warning, and TV producers are ignoring it, too, using tricks of time to rev up storylines and add excitement to tired genres.

For television, embracing the fourth dimension can mean everything from setting a show entirely in the past (“Mad Men”) or future (“Terminator: The Sarah Connor Chronicles”), to outright leaps, as on “Heroes,” to flashes forward and backward, a la “Lost.”

Flashbacks were hardly a new dramatic device when “Lost” began telling its stories that way in 2004. But those flashbacks turned out to be a smokescreen hiding the pivotal role time would play on “Lost,” where clocks are useless, the past regularly invades the present and characters jump around in their own circular histories.

All has not yet been revealed, but since the 2007 decision to end the series in May 2010, “Lost” has continued on two timelines, one in the present (rather, the past) and the other in the future (or potentially the present).

Marc Cherry watched “Lost” play with time and was emboldened. The “Desperate Housewives” creator was so impressed with the “bold stroke” by “Lost” executive producers Damon Lindelof and Carlton Cuse, he said, that he thought, “Let's just go forward in time. Let me change everyone's lives completely.”

So fans who tuned in for the Season 5 premiere of “Desperate Housewives” found the Scavo kids all grown up and Gabrielle Solis (Eva Longoria Parker) a frumpy housewife with two little girls. An opening voice-over made it clear that the story had jumped ahead five years.

And don't expect “Housewives” ever to return to its past. “There will be some bouncing, but for the most part, we're going five years and committing to it,” executive producer Bob Daily said. “I think the fun for us and the audience is revealing in dribs and drabs what you missed in those five-year periods.”

ABC's “Life on Mars,” adapted from a British series, aims for “a whole new way of telling cop stories” by taking a New York cop from 2008 and planting him on “Mars” – meaning 1973. Attuned to modern crime-solving, Sam Tyler (Jason O'Mara) has been thrust into a time before cell phones and DNA evidence, and “it will be a great source of conflict,” said executive producer Josh Applebaum.

The British series, which ran just 16 episodes, wound up with the lead character turning out to be in a coma. But that felt unsatisfying to producers of the American version.

“We are changing the mythology,” Applebaum said. “Each week, we'll be deepening that mystery of what's going on with him. …”

Added executive producer Andre Nemic: “Though, to be clear, it is not a time-travel show. We are not going back and forth between 2008 and 1973.”