SACRAMENTO, Calif. (AP) – California is imposing a nighttime curfew as its coronavirus figures soar but it will lean heavily on voluntary compliance and sheriffs of some counties say they won’t enforce it. The stay-at-home order for Kern and 40 other counties bars nonessential travel and closes nonessential businesses from 10 p.m. to 5 a.m. starting Saturday. The order will last until Dec. 21 and comes as a surge in COVID-19 cases threatens to overwhelm the health care system. The curfew covers 94% of the state’s nearly 40 million residents. But sheriffs and some lawmakers in at least four counties say they won’t enforce the curfew.