Boston is 3 hours ahead of San Francisco. When it's 9:00 AM in San Francisco, it's 12:00 PM (noon) in Boston. This difference remains constant year-round as both states observe daylight saving time on the same schedule.
San Francisco operates on Pacific Time (PT), while Boston uses Eastern Time (ET). Both California and Massachusetts follow the same DST rules, so the 3-hour difference is consistent throughout the year.
Optimal meeting window: 9:00 AM - 2:00 PM San Francisco time (12:00 PM - 5:00 PM Boston). This catches afternoon business hours in Boston while being morning to early afternoon in San Francisco.
Both cities are major tech and biotech hubs. Silicon Valley and Boston's Route 128 corridor have extensive business connections, making this one of the most common US coast-to-coast business routes.