Chicago is 1 hour behind Arequipa during standard time (CST, UTC-6). When the US observes DST (CDT, UTC-5), both cities are on the same time.
When it's 12:00 PM in Arequipa, it's 11:00 AM in Chicago (winter) or 12:00 PM (summer). Peru does not observe DST.
Business hours overlap almost entirely. Call anytime between 9:00 AM - 6:00 PM in either city for convenient scheduling.
Chicago has a significant Peruvian community. The city is also a major air hub with connections to South America through O'Hare International Airport.