The Chinese Almanac (黄历, Huang Li), also called the Tong Shu, is a daily guide used for centuries to choose lucky timing for important events.
Each day lists activities that are favored — things like opening a business, moving house, getting married, or starting a journey. Doing these on a "yi" day is believed to align with good energy.
Activities to avoid that day — for example, signing contracts, breaking ground, or holding a wedding. Avoiding these is thought to prevent friction.
The almanac combines the day's Heavenly Stem and Earthly Branch, the lunar date, the 28 lunar mansions, and various stars. It's deterministic — calculated, not guessed.
For entertainment and self-reflection purposes only.