There is no time difference between Berlin and Vienna. Both cities use Central European Time (CET/CEST, UTC+1/+2). When it's 12:00 PM in Berlin, it's also 12:00 PM in Vienna.
Both cities observe daylight saving time on the same schedule, so they remain synchronized year-round.
Any time works! Since both cities share the same timezone, you can schedule calls during standard business hours (9:00 AM - 6:00 PM) without any time conversion needed.
Berlin and Vienna are two German-speaking capitals with rich cultural and historical connections. Both were centers of power in their respective empires and today are major European capitals. Direct flights take about 1.5 hours, or trains about 9 hours.