While some might joke that California, is in a world of its own, it’s actually part of the U.S. Pacific Standard Time Zone (PST). If you live on the east coast and are part of the Eastern Standard Time Zone (EST), like New York, a city like San Diego will be three hours behind you. In other words, if it’s noon in New York, it’s 9:00 in the morning in San Diego. If you live in the Central Standard Time Zone (CST), like Kansas City, San Diego will be two hours behind. And finally for those in Mountain Standard Time (MST) like Colorado, San Diego will be one hour behind.