Mumbai is 13 hours and 30 minutes ahead of San Francisco during standard time (or 12.5 hours during PDT). San Francisco uses Pacific Time (PT, UTC-8/-7) while Mumbai uses Indian Standard Time (IST, UTC+5:30). When it's 12:00 PM in San Francisco, it's 1:30 AM the next day in Mumbai.
India does not observe daylight saving time, so the difference varies between 12.5 and 13.5 hours depending on whether San Francisco is on PST or PDT.
Best calling time: 6:00 AM - 8:00 AM San Francisco time. This corresponds to 7:30 PM - 9:30 PM in Mumbai (or 6:30 PM - 8:30 PM during PST), catching Indian evening hours.
San Francisco and Mumbai are both major financial and tech centers. Many Silicon Valley companies have offices in Mumbai, and India's financial capital has strong ties to California's venture capital ecosystem. Direct flights connect them in about 17-18 hours.