So nowadays in Chinese, Monday is called 星期一, literally means day 1 of the Week, Tuesday is called 星期二, literally means day 2 of the week, and so on and so forth, with the exception of Sunday 星期天, which literally means Sun-day.
But I'm curious, what was the name of days in Ancient China? Answers from Zhou Dynasty to Qing Dynasty are all accepted as I wanted to know it them all.
A set of names seen in Classical Chinese for the 7 day week are:
The mandarin for these are: rìyàorì yuèyàorì huǒyàorì shuǐyàorì mùyàorì jīnyàorì tǔyàorì. These day names are still used in Japan, written the same but pronounced as nichiyōbi getsuyōbi kayōbi suiyōbi mokuyōbi kin'yōbi doyōbi. (These pronounciations are quite different as the words were borrowed from Middle Chinese (中古漢語) into Early Middle Japanese. In those, relations such as 月曜 MC ngüetyèu- > EMJ getuyeu- > JP getsuyō- and 木曜 MC mowkyèu- -> EMJ mokuyeu- -> JP mokuyō- become more obvious. The -bi and -rì, although similar looking, are unrelated words for 'day' and coincidental. )
If some of those Classical Chinese names seem familiar compared to the day names in English or Romance languages, it's because they both ultimately stem from the same source. The original association between a 7 day week and the 7 moving objects in the sky (termed in Chinese and Japanese "the Seven Luminaries", 七曜) was created in the Near East, possibly in Babylon. The system spread both east and west through its use in astrology and astronomy.
The Chinese appear to have adopted the 7 day week in the 8th century from interactions with central asians, who would have picked it up from Persia or India. It remained mostly used for astronomy/astrology except among Christians, Muslims, and others for whom a seven day week was necessary. I've heard claims that it also was mentioned by some writers during the Sima Jin dynasty (though seemingly not extensively used), but I don't know much about its usage during that period. It seems agreed upon that in the Three Kingdoms period and prior there was no usage of a 7 day week in at all.
These were definitely in use in the Tang Dynasty period, and are the standard way of referring to the seven days in Classical Chinese writing. However, they weren't used as often as the days of the week are today. The 7-day week was not commonly used for normal daily life, and months were instead divided into 10-day periods called 旬 (Mandarin Xún, Japanese Jun). Applying the sexagenary cycle (干支) to count days was also used, and was common in the Shang Oracle Bones at least until the Han Dynasty. The familiar western 7-day weeks only became important to most people's daily lives in China in the 19th century after long interaction with european traders and missionaries, and especially after the Xinhai Revolution when the western Gregorian Calendar was formally adopted.