The Japanese electric current is 100V AC, which is found almost nowhere else in the world. Most North American electrical items, designed to run on 117V, will work reasonably well on the Japanese current. All of Japan is on the same time zone and there is no daylight-savings. Japan is fourteen hours ahead of Eastern Standard Time in the US and nine hours ahead of Greenwich Mean Time in Britain. Accordingly, when it is noon in Japan, it is 7pm the previous day in San Francisco 10pm in New York, 3am in London, 11am in Hong Kong, and 1pm in Sydney.
Japan uses the international metric system except when measuring the size of rooms.
In this case the measurement is made by how many tatami mats or 'jo' fit into the space.