Perpetual Calendar
View solar calendar, lunar calendar, solar terms, and holidays. Supports year and month switching.
Calendar Use Cases
- View lunar and solar calendar dates for any month, ideal for traditional holiday lookup
- Plan schedules by quickly identifying weekdays and weekends
- Look up lunar dates for specific days, useful for traditional customs and ceremonies
- Verify exact dates for important anniversaries and holidays
- Understand the varying number of days across months for better planning
Frequently Asked Questions
What years can this calendar display?
This perpetual calendar supports dates from 1900 to 2100, covering 201 years of complete date data. You can freely switch between any year and month to view corresponding solar and lunar calendar information.
How are lunar calendar dates calculated?
The lunar calendar is a traditional Chinese lunisolar calendar. Months are determined by the moon's synodic cycle (approximately 29.5 days), and leap months are inserted to align with the solar year. This tool provides simplified lunar dates; precise calculations require professional astronomical data.
Why are some dates shown in gray?
Gray dates belong to months other than the currently selected one. The calendar grid displays trailing dates from the previous month and leading dates from the next month to fill the 6×7 layout, helping you see the complete date context.
Solar and Lunar Calendar Relationship
The solar calendar (Gregorian calendar) is the internationally adopted standard, based on Earth's revolution around the sun with 365 days per year (366 in leap years). The lunar calendar is China's traditional calendar system, combining solar and lunar cycles where months follow lunar phases.
Due to the difference between the solar year and lunar cycle, a leap month is added every 2-3 years to correct the offset. The 24 solar terms are an important component, dividing the sun's position on the ecliptic into 24 segments to guide agriculture and daily life.