Perpetual Calendar - Free Online Tool | PivaBox

Chinese perpetual calendar with lunar dates, zodiac signs, and heavenly stems & earthly branches

Chinese Perpetual Calendar (万年历) — View Gregorian Dates Alongside Lunar Calendar, Heavenly Stems, Earthly Branches, Zodiac Signs, and Solar Terms

1. Browse the dual-display calendar grid showing both Gregorian (solar) dates in the main cells and Chinese lunar dates (农历) displayed beneath each day. The Chinese lunisolar calendar is one of the world's oldest continuously used calendar systems, dating back over 3,000 years to the Xia and Shang dynasties. Each month begins with the new moon, and the year is kept synchronized with the solar year through the insertion of leap months (闰月, rùnyuè) approximately every three years — the calendar explicitly marks these intercalary months when they occur.
2. Click any date in the grid to reveal detailed traditional Chinese calendar information in the side panel, including: the Lunar Date (农历日期) showing the month, day, and whether it's a leap month; the Heavenly Stems and Earthly Branches (天干地支, Tiāngān Dìzhī) designation for the year — the 60-year sexagenary cycle that combines 10 heavenly stems (甲 乙 丙 丁 戊 己 庚 辛 壬 癸) with 12 earthly branches (子 丑 寅 卯 辰 巳 午 未 申 酉 戌 亥); the Chinese Zodiac animal (生肖, shēngxiào) associated with the selected year's earthly branch; and any Solar Term (节气, jiéqì) that falls on that date — the 24 solar terms that divide the year based on the sun's position along the ecliptic.
3. Navigate between months and years using the arrow buttons or the month/year dropdown selectors. The calendar covers a 200-year range from 1900 to 2100, encompassing the full lookup table period for the traditional Chinese lunar calendar. Each date cell also displays traditional almanac information (黄历, huánglì) including auspicious activities (宜, yí) and inauspicious activities (忌, jì) — these are the traditional Chinese cultural recommendations for what activities are favorable or unfavorable on a given day, commonly consulted for wedding dates, business openings, travel planning, and important life events.

Frequently Asked Questions

How does the Chinese lunar calendar differ from the Gregorian calendar, and why are they both shown together?

The Gregorian calendar is a purely solar calendar — each year has 365 days (366 in leap years) divided into 12 fixed months unrelated to the moon. The Chinese calendar is lunisolar — each month begins with the astronomical new moon (making months 29 or 30 days long), and the year averages 354 days. To prevent seasonal drift, a leap month is inserted approximately every 3 years (7 times in 19 years), creating leap years of 383–385 days. This dual nature means the Chinese New Year (春节) falls on a different Gregorian date each year — between January 21 and February 20. The PivaBox Perpetual Calendar displays both systems side by side because most people in Chinese-speaking regions live by the Gregorian calendar for daily business while consulting the lunar calendar for traditional festivals, holidays, and cultural observances. All calendar calculations are performed locally in your browser using established lookup tables and astronomical algorithms.

What are the Heavenly Stems and Earthly Branches (天干地支), and how are they used to name years?

The Heavenly Stems (天干, Tiāngān) are a set of 10 symbols (甲 乙 丙 丁 戊 己 庚 辛 壬 癸), and the Earthly Branches (地支, Dìzhī) are a set of 12 symbols (子 丑 寅 卯 辰 巳 午 未 申 酉 戌 亥). They combine in a 60-year cycle (the sexagenary cycle, 干支纪年) — the first stem pairs with the first branch (甲子), then each advances by one (乙丑, 丙寅...), creating 60 unique pairs before repeating. This system has been used continuously in China for over 3,000 years to name years, months, days, and even hours of the day (each two-hour period is assigned an earthly branch). 2024 is a 甲辰 (Jiǎchén) year — Wood Dragon. The earthly branch of the year also determines the Chinese Zodiac animal: 子=Rat, 丑=Ox, 寅=Tiger, 卯=Rabbit, 辰=Dragon, 巳=Snake, 午=Horse, 未=Goat, 申=Monkey, 酉=Rooster, 戌=Dog, 亥=Pig. The PivaBox calendar shows both the stem-branch designation and the zodiac animal for each year.

What are the 24 Solar Terms (二十四节气) and how do they relate to the lunar calendar?

The 24 Solar Terms (二十四节气, Èrshísì Jiéqì) are a uniquely Chinese invention that divides the solar year into 24 segments based on the sun's position along the ecliptic (15° increments). Unlike lunar months which follow the moon, solar terms are purely solar — they fall on approximately the same Gregorian dates each year. The terms guide agricultural activities: Lìchūn (立春, Start of Spring, ~Feb 4), Yǔshuǐ (雨水, Rain Water, ~Feb 19), Jīngzhé (惊蛰, Awakening of Insects, ~Mar 6), and so on through 21 more terms culminating in Dàhán (大寒, Major Cold, ~Jan 20). The terms are so accurate for agricultural timing that they remain widely used by farmers today — the system was inscribed on UNESCO's Representative List of the Intangible Cultural Heritage of Humanity in 2016. The PivaBox Perpetual Calendar marks solar terms on their corresponding dates, providing both the Chinese name and the English translation. All calendar data is computed locally in your browser — your usage history and date selections remain completely private.