the chinese transliteration of the planetary system was soon brought to japan by the japanese monk kobo daishi; surviving diaries of the japanese statesman fujiwara michinaga show the seven-day system in use in heian period japan as early as 1007. in japan, the seven-day system was kept in use (for astrological purposes) until its promotion to a full-fledged (western-style) calendrical basis during the meiji era. in china, with the founding of the republic of china in 1911, monday through saturday in china are now named after the luminaries implicitly with the numbers.