The CW is adding to its midseason roster, picking up the Sean Hayes-produced laffer “Eight Days a Week.”Pop singer Christina Milian and Mario Lopez star in the comedy, which revolves around four Gothamites in their 20s who work for some of the city’s most powerful people. They’ve largely given up on their personal lives in order to get ahead and are forced to rely on each other for support. The CW has ordered 13 episodes of “Eight Days a Week.” Meredith Lavender and Marcie Ulin wrote the pilot and will produce. Hayes and Todd Milliner will exec produce via their Hazy Mills banner. CBS Par Network Television and Warner Bros. TV are attached as studios.