Delhi 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 Delhi 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 Delhi.
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 Delhi (or 6:30 PM - 8:30 PM during PST), catching Indian evening hours.
San Francisco's tech industry has extensive connections with India, particularly for software development and IT services. Many Silicon Valley companies have offices in Delhi NCR. The India-California tech corridor is one of the world's most important.