Japanese calendar
Japanese Romanization Element ( planet ) English name
日曜日 nichiyōbi Sun Sunday
月曜日 getsuyōbi Moon Monday
火曜日 kayōbi Fire ( Mars ) Tuesday
水曜日 suiyōbi Water ( Mercury ) Wednesday
木曜日 mokuyōbi Wood ( Jupiter ) Thursday
金曜日 kin'yōbi Metal ( Venus ) Friday
土曜日 doyōbi Earth ( Saturn ) Saturday
Official calendar -- Subdivisions of the month
Japan uses a seven-day week , aligned with the Western calendar . The seven-day week , with names for the days corresponding to the Latin system , was brought to Japan around AD 800 with the Buddhist calendar . The system was used for astrological purposes and little else until 1876 . The names of the days come from the five visible planets , which in turn are named after the five Chinese elements ( metal , wood , water , fire , earth ) , and from the moon and sun ( yin and yang ) . On the origin of the names of the days of the week , also see East Asian Seven Luminaries .
Japanese calendar types have included a range of official and unofficial systems. At present, Japan uses the Gregorian calendar together with year designations stating the year of the reign of the current Emperor.