Люди не подскажите какой формат времени в Японии? 12-ти часовой или 24-ёх часовой?

Оба формата. Есть и отличия в 12 часовом. . Например 12 AM записывается как в случае 24 часового - нулем. Аналогично и полдень - вместо 12 PM

http://en.wikipedia.org/wiki/Date_and_time_notation_by_country#Japan

Using the Japanese notation, times are written as "8時42分", with the characters for "hour" and "minute" (optionally also 秒 for "seconds") added after the numerals. It is also common to simply write 8:42 though. Japan uses 24-hour times, nevertheless 12-hour notation is also often found, using the markers 午前 ("before noon") and 午後 ("after noon"). When using 12-hour notation, both noon and midnight are written as 0, e.g 午後0時15分 or 0:15 for "quarter past noon". The time is usually pronounced as "12:15" or "15 minutes past noon" though.

и могут даже "заходить" за полночь - для бизнес времени :))) например 2 ночи будет записано как 26 часов :)

Times past midnight can also be counted past the 24 hour mark, usually used when the associated activity spans across midnight. For example, bars or clubs may advertise as being open until "26時" (2 a.m.). This form is rarely used colloquially.