What does the Gregorian calendar mean?

Gregorian calendar is a traditional lunar calendar, also known as "general book", "perpetual calendar" and "imperial calendar". The Gregorian calendar records the year, month, day, solar terms, festivals and good or bad luck of the lunar calendar. It is an important part of China traditional culture, and is widely used in the fields of geomantic omen, health preservation, folk customs and so on. Almanac is usually compiled by professional numerologists or almanac compilers, which contains rich knowledge of astronomy, geography, history, culture and folk customs, and is regarded as an ancient and mysterious cultural heritage.