What is the Solar Lunar Converter?

The Solar Lunar Converter is a bidirectional date conversion tool that lets you convert between the Gregorian (solar) calendar and the traditional lunar calendar used across East Asia. Whether you need to find the lunar equivalent of a Gregorian date or determine the solar date for a specific lunar day, this tool handles both directions seamlessly.

Beyond simple date conversion, the tool displays rich almanac information for every converted date, including Can Chi (Heavenly Stems and Earthly Branches), zodiac animals, solar terms, and traditional holidays relevant to your locale.

Why You Might Need This Tool

Millions of people in East Asia rely on the lunar calendar for cultural events, traditional ceremonies, and personal milestones. Common use cases include:

Lunar Birthdays

Many people celebrate their birthday on the lunar date. This tool makes it easy to find the corresponding solar date each year.

Traditional Holidays

Plan around holidays like Tet, Chinese New Year, Mid-Autumn Festival, and Chuseok that fall on specific lunar dates.

Can Chi & Zodiac

Understanding the Can Chi designation and zodiac animal for a given date is important for traditional practices and ceremonies.

Leap Month Handling

The lunar calendar occasionally inserts a leap month to stay aligned with the seasons. This tool automatically detects leap months for any year.

Supported Traditions

The converter adapts its output based on your language setting, covering the three major East Asian lunar calendar traditions:

Vietnamese

Authentic Vietnamese lunar calendar tradition with unique characteristics:

Cat zodiac (instead of Rabbit)
Vietnamese Can Chi names
Tet Nguyen Dan and Vu Lan holidays

Chinese

Traditional Chinese lunar calendar system:

Rabbit zodiac
Chinese Gan Zhi names
Spring Festival and Dragon Boat Festival

Korean

Korean lunar calendar tradition:

Rabbit zodiac
Korean Gapja names
Seollal and Chuseok holidays

Table of Contents

1. What is the Solar Lunar Converter?
- 1.1. Why You Might Need This Tool
- 1.2. Supported Traditions
2. How to Use the Solar Lunar Converter
3. Features
4. Frequently Asked Questions

How to Use the Solar Lunar Converter

Converting a Solar Date to Lunar

When you first open the tool, it defaults to Solar to Lunar mode:

Open Date Picker

Click the date input field to open the date picker calendar

Select Date

Select any date from the calendar, or type a date directly

View Result

The result card immediately displays the corresponding lunar date with full almanac details

Quick Tip: Click the Today button at any time to quickly return to the current date.

Converting a Lunar Date to Solar

To convert in the other direction:

Switch Mode

Click the Lunar to Solar tab at the top

Select Date Components

Select the year, month, and day from the dropdown menus. Years that contain a leap month are marked with a ✦ symbol (for example, "2025 ✦")

Handle Leap Months

If the selected year has a leap month, an additional option appears automatically in the month dropdown (for example, "6 (Leap)")

View Conversion

The result card updates with the solar date and all associated almanac information

Using the Swap Feature

The swap button (between the input and result areas) reverses the conversion direction while carrying over the current result. For example, if you just converted February 17, 2026 to Lunar Month 1 Day 1, clicking swap switches to Lunar to Solar mode with those lunar values pre-filled.

Reading the Result Card

The result card displays information in two columns:

Solar Column

Gregorian Information

Day number
Month and year
Day of the week

Lunar Column

Lunar Information

Lunar day number
Month name
Can Chi for month and day
Zodiac animal with image
Current solar term
Traditional holiday (if applicable)

Copying Results

Click the Copy Result button to copy a formatted summary of both dates, Can Chi, zodiac, solar term, and holiday information to your clipboard. This is useful for sharing or recording date conversions.

Conversion History

Every conversion is automatically saved to your local history (up to 10 entries). Click the History bar to expand the list, and click any entry to quickly re-run that conversion. Use the Clear button to remove all history. History persists across page reloads.

Features

Bidirectional Conversion

Convert in either direction with a single toggle: Solar (Gregorian) to Lunar, or Lunar to Solar. The interface adapts its input method for each mode — a date picker for solar input, and cascading dropdowns for lunar input.

Automatic Leap Month Detection

Years containing a leap month are marked with a ✦ symbol in the year dropdown for quick identification. Selecting such a year causes the month dropdown to automatically include the leap month option, eliminating guesswork.

Visual leap year indicators
Automatic leap month options
Dynamic day count adjustment (29 or 30 days)

Rich Almanac Information

Every conversion result includes detailed traditional calendar data beyond the basic date:

Can Chi — Heavenly Stems and Earthly Branches for year, month, and day
Zodiac animal — Visual icon with animal designation
Solar terms — 24 seasonal markers highlighted with green badges
Traditional holidays — Cultural celebrations shown with red badges

Instant Swap

The swap button reverses the conversion direction while carrying over the current result values. This makes it easy to check both the solar and lunar sides of any date without re-entering information.

Copy to Clipboard

Copy a complete, formatted summary of the conversion result with one click. The copied text includes both dates, Can Chi, zodiac animal, solar term, and holiday information.

Conversion History

Up to 10 recent conversions are stored locally in your browser. Click any history entry to instantly restore and re-run that conversion. History persists across page reloads and can be cleared at any time.

Multi-Locale Support

The tool adapts all terminology, Can Chi names, zodiac animals, holiday names, and date formatting based on your language setting.

Vietnamese (with Cat zodiac)
Chinese Simplified (with Rabbit zodiac)
Korean (with Rabbit zodiac)

Server-Side Initial Rendering

The first page load displays today's conversion result rendered on the server, ensuring fast loading and search engine visibility. All subsequent conversions are handled dynamically through API calls for a smooth, responsive experience.

Frequently Asked Questions

What is the difference between the solar and lunar calendar?

The solar (Gregorian) calendar is based on Earth's orbit around the Sun, with fixed month lengths totaling 365 or 366 days per year. The lunar calendar is based on the Moon's phases, with each month beginning on a new moon.

A lunar month averages about 29.5 days, making the lunar year approximately 11 days shorter than the solar year. Periodic leap months are inserted to keep the two calendars roughly aligned.

Solar Calendar

Based on Earth's orbit around Sun
Fixed month lengths
365-366 days per year
Consistent with seasons

Lunar Calendar

Based on Moon's phases
Variable month lengths (29-30 days)
~354 days per year
Requires leap months for alignment

What is a leap month in the lunar calendar?

A lunar leap month is an extra month inserted into certain years to synchronize the lunar calendar with the solar year. About every 2–3 years, a 13th month is added.

Automatic Detection: This tool automatically detects leap months for any selected year and shows them in the month dropdown, so you do not need to calculate this yourself.

How do I convert my birthday from solar to lunar?

Select Solar to Lunar mode, then pick your birth date using the date picker. The result card will show your corresponding lunar birthday along with Can Chi details and your birth year's zodiac animal.

Switch to Solar to Lunar mode
Enter your birth date
View your lunar birthday in the result card
Note the zodiac animal and Can Chi information
Use the Copy button to save the information

Why does the Vietnamese zodiac have a Cat instead of a Rabbit?

In the Vietnamese tradition, the fourth zodiac animal is the Cat (Meo) rather than the Rabbit. The exact historical reason is debated, but a common theory relates to the similar pronunciation of the Earthly Branch "Mao" and the Vietnamese word for cat.

Locale-Specific: When you use this tool with Vietnamese selected, the Cat zodiac is displayed correctly, while Chinese and Korean locales show the Rabbit.

What is Can Chi?

Can Chi (Gan Zhi in Chinese, Gapja in Korean) is a traditional cycle combining 10 Heavenly Stems with 12 Earthly Branches to create a 60-unit repeating cycle. It is used to designate years, months, days, and hours in the East Asian calendar system.

The converter shows the Can Chi for the month and day of any converted date, as well as the year designation alongside the zodiac animal.

10 Heavenly Stems

Represent the five elements (Wood, Fire, Earth, Metal, Water) in their Yang and Yin forms

12 Earthly Branches

Correspond to the 12 zodiac animals and represent different time periods

What are solar terms?

Solar terms (Tiet Khi in Vietnamese, Jieqi in Chinese) are 24 points in the year determined by the Sun's position along the ecliptic. They mark seasonal transitions and have been used for centuries in agriculture and traditional practices.

When a converted date falls on or near a solar term, it is shown with a green badge in the result card.

Agricultural Significance: Solar terms were traditionally used to guide farming activities, indicating optimal times for planting, harvesting, and other agricultural tasks.

How accurate are the date conversions?

This tool uses the established 6tail/lunar-php library for all lunar calendar calculations. The library provides highly accurate conversions covering a wide range of years, properly accounting for leap months, varying month lengths, and regional calendar differences.

Accurate leap month detection
Proper handling of varying month lengths
Regional calendar differences respected
Wide year range support
Verified against traditional almanacs

Is my data stored anywhere?

Conversion history is stored only in your browser's local storage. No personal data is uploaded to any server. Each conversion makes an API call to calculate the result, but no user data is retained server-side.

Privacy First: Your conversion history stays on your device. You can clear it at any time using the Clear button in the history panel.