San Juan is typically 2 hours ahead of Chicago. When it's 10:00 AM in Chicago, it's 12:00 PM (noon) in San Juan. During daylight saving time (March to November), the difference reduces to 1 hour since Puerto Rico does not observe DST.
San Juan uses Atlantic Standard Time (AST/UTC-4) year-round, while Chicago operates on Central Time (CT). Puerto Rico, like most Caribbean islands, does not observe daylight saving time.
Good overlap: 8:00 AM - 5:00 PM Chicago time (9:00 AM - 6:00 PM or 10:00 AM - 7:00 PM San Juan, depending on DST). The small time difference makes scheduling convenient.
Chicago has a significant Puerto Rican community, and business connections between these cities are common. The modest time difference makes same-day communication easy throughout the year.