Steve Buscemi in “Boardwalk Empire.” (Macall B. Polay /HBO)

Two HBO drama series, “Boardwalk Empire” and “Treme,” will both return for third seasons in September, the network announced Monday.

This is business as usual for “Boardwalk,” the Prohibition-era drama starring Steve Buscemi as a corrupt politician in Atlantic City, which has debuted around mid-September for the past two seasons. This year, it will premiere Sept. 16, right about the same time the broadcast networks unleash all the new fall shows.

However, “Treme,” which follows the lives of New Orleans residents after Hurricane Katrina, gets a Sept. 23 premiere date, months later than its usual April start time.