Chinese uses the numbers for days of the week, so 星期一,星期二,星期三,星期四,星期五,星期六,星期日 for Monday to Sunday. They can use 周 or 礼拜 instead of 星期.
I remembered Japanese copied the Chinese at something there, but, whoops, it was the names of the planets that were copied. So the Chinese names of Mars(火星), Mercury(水星), Jupiter(木星), Venus(金星), and Saturn(土星) are copied onto the same days as planets that Romance languages name their days after.
