The traditional Chinese time systems refers to the time standards for divisions of the day used in China until the introduction of the Shixian calendar in 1628 at the beginning of the Qing dynasty. Han-era system The third chapter of the Huainanzi outlines 15 hours during daylight. These are dawn (), morning light (), daybreak (), early meal (), feast meal (), before noon (), noon (), short shadow (), evening (), long shadow (), high setting (), lower setting(), sunset (), twilight (), rest time (). These are correlated to each hour from 06:00 to 20:00 on the 24-hour clock. Eastern Han to Ming system This system used two standards to measure the time in a solar day. Times during daylight were measured in the Shí-kè standard, and at night were measured using the Gēng-diǎn standard. During daylight: Shí-kè The Shí-kè ( - ) system is derived from the position of the sun. Dual hour: Shí Each shí () was of the time between one midnight and the next, making it roughly double the modern hour. These dual hours are named after the earthly branches in order, with midnight in the first shí. This first shí traditionally occurred from 23:00 to 01:00 on the 24-hour clock with midnight in the middle of the first shí, but was changed during the Song dynasty so that the first shí fell from 00:00 to 02:00 with midnight at the beginning of it. Starting from the end of the Tang Dynasty into the Song Dynasty, each shí was divided into two, with the first half of each shí called the initial hour () and the second called the central hour (). Using the change of the midnight hour and the first shí above, you could say that during the Song Dynasty midnight went from the central hour of the first shí () to the initial hour of the first shí (). One-hundredth of a day: Kè Days were also divided into smaller units, called kè (). One kè was usually defined as of a day until 1628, though there were short periods before then where days had 96, 108 or 120 kè. Kè literally means "mark" or "engraving", referring to the marks placed on sundials or water clocks to help keep time. Using the definition of kè as of a day, each kè is equal to 0.24 hours, 14.4 minutes, or 14 minutes