Chicago is 2 hours ahead of San Diego. San Diego uses Pacific Time (PT, UTC-8/-7) while Chicago uses Central Time (CT, UTC-6/-5). When it's 12:00 PM in San Diego, it's 2:00 PM in Chicago.
Both cities observe daylight saving time on the same schedule, so the 2-hour difference remains constant throughout the year.
Best calling time: 7:00 AM - 3:00 PM San Diego time. This corresponds to 9:00 AM - 5:00 PM in Chicago, covering full business hours.
San Diego and Chicago are both major US cities with thriving economies. San Diego is known for biotech and defense, while Chicago is a financial hub. Direct flights connect them in about 4 hours.