Detroit and Indianapolis are in the same time zone. Both cities use Eastern Time (EST/EDT). When it's noon in Detroit, it's also noon in Indianapolis.
Both cities observe daylight saving time, switching between EST (UTC-5) in winter and EDT (UTC-4) in summer.
Any time works! Since both cities are in the same time zone, scheduling calls is never a problem. Business hours are identical.
Detroit and Indianapolis are about 4.5 hours apart by car. Both are major Midwest industrial centers with strong automotive connections.