Patting a U.S. colleague on the back for congratulations is a common practice, but in Japan it would be discourteous. Clothes, expressions, posture, and actions are all important considerations in conducting international business. Another important consideration is religious and national holidays. Trying to conduct business on the Fourth of July in the United States would be difficult, if not impossible. Likewise, different dates have special significance in various countries.
Some countries have long holidays by our standards, making business difficult.
For example, doing business is difficult in Saudi Arabia during the month of fasting before the Ramadan religious festival. Numerous seminars, film series, books, and publications exist to help the overseas traveler. Try to obtain cultural information from business colleagues who have been abroad or have expertise in a particular market. A little research and observation in cultural behavior can go a long way in international commerce. Likewise, a lack of sensitivity to another's customs can stop a deal in its tracks.