The huangli (黄历) is the traditional almanac. Besides dates and solar terms, it lists for every day what is auspicious and what should be avoided (宜 and 忌). It is used to choose a good day. The Handian dictionary explains the old custom of 看日子, choosing a day: people usually asked a fengshui master or consulted the huangli.
The name goes back to the calendars once compiled by the court and issued in the emperor’s name, the “imperial calendar” (皇历). Because they often had yellow covers, they were also called the “yellow calendar.”