During the Edo period (1603 - 1868), the Japanese clock was divided into twelve units of time, or ˉhoursˇ, with each one named after one of the zodiacal symbols of the lunar calendar, and with the day being divided up into six daytime hours and six night-time hours. This woodblock print is taken from Kitagawa Utamaro's 1794-1795 ukiyo-e series 'Twelve Hours of the Green Rooms', sometimes styled 'Twelve Hours of the Yoshiwara', featuring everyday events in the lives of courtesans in Edo's Yoshiwara pleasure district. The hour of the Rat corresponds roughly to midnight. This is the moment that the courtesan puts on her night attire to join her client in bed, while her apprentice carefully folds the dress she wore earlier to attend the banquet.