About Feng Shui Calendar

Calculation methodology

The app calculates the rating for each day based on three independent systems derived from the Tong Shu almanac:

12 Day Officers (建除十二神 Jian Chu) — each day in the lunar calendar is assigned one of twelve officers. The Jian Chu system dates from the Han Dynasty (206 BCE – 220 CE) and forms the core of the practical almanac.

28 Lunar Mansions (二十八宿 Xiu) — the lunar zodiac divided into 28 stations through which the Moon passes each month. Each mansion has associated auspicious and inauspicious activities.

Ba Zi (八字) and Five Elements (五行 Wu Xing) — the user's personal element calculated from their birth year in the lunar calendar. The relationship between the day's element and the user's element influences the day rating.

The algorithm also accounts for zodiac clashes (六冲) and harm (六害) — special relationships between the user's sign and the earthly branch of a given day.

Sources and foundations

The calculations are based on classical texts and modern works on traditional Chinese astrology:

• Tong Shu (通書) — Chinese almanac in traditional and simplified form

• Heavenly Stems & Earthly Branches system (天干地支 Tianganzhi) — the 60-year Chinese calendar cycle

• Traditional Chinese lunisolar calendar (農曆) with Chinese New Year date calculation

• Jieqi (节气) — 24 Solar Terms marking energy shifts throughout the year

The lunar calendar algorithm is based on the lunar-javascript library using astronomical data from 1900 to 2100.

What this app is not

Feng Shui Calendar is an educational and planning tool based on cultural tradition. It does not replace a professional Feng Shui consultant, who considers a full Ba Zi chart (year, month, day, hour of birth), spatial orientation and individual circumstances.

Day ratings should be treated as guidance, not absolute predictions. The Tong Shu tradition itself emphasizes that "a good day helps, a bad day does not destroy".

Privacy and data

The app collects no personal data and requires no registration. The only information stored locally in your browser is your selected zodiac sign and display preferences. No data is sent to external servers.