Beijing is 16 hours ahead of San Francisco during standard time (or 15 hours during PDT). San Francisco uses Pacific Time (PT, UTC-8/-7) while Beijing uses China Standard Time (CST, UTC+8). When it's 12:00 PM in San Francisco, it's 4:00 AM the next day in Beijing.
China does not observe daylight saving time, so the difference varies between 15 and 16 hours depending on whether San Francisco is on PST or PDT.
Best calling time: 5:00 PM - 7:00 PM San Francisco time. This corresponds to 9:00 AM - 11:00 AM the next day in Beijing, catching Chinese morning business hours.
San Francisco and Beijing have extensive tech and business connections. Many Silicon Valley companies have offices or partnerships in Beijing. The large Chinese-American population in San Francisco maintains strong cultural and business ties to China.