The lunar calendar tool
Solar to Vietnamese lunar date and back, with leap months and the can-chi year. A conversion only — no lucky-day claims.
What it does
The lunar calendar converter turns any solar (Gregorian) date between 1900 and 2199 into the Vietnamese lunar date and back. It reports the day, the month (with a leap-month flag), the year's can-chi name — Đinh Mùi, Ất Tỵ — and the weekday. Everything runs in your browser; nothing is sent anywhere.
How it is calculated
Dates are computed astronomically for Vietnam (UTC+7) with the Hồ Ngọc Đức method, the same approach printed calendars use. Because Vietnam and China sit in different time zones, a new moon close to midnight can put the first of the month on different days in the two calendars; the tool follows the Vietnamese one.
A few pairs you can check against any lịch vạn niên: 29 January 2025 is Tết — 1/1 of Ất Tỵ; 10 February 2024 is 1/1 of Giáp Thìn; 2025 has a leap sixth month; 16 October 2027 is the 17th day of the 9th month of Đinh Mùi (the 16th of that month is 15 October). The page recomputes these pairs on every load and shows a green tick next to each.
What it does not do
It does not pick "good days". Choosing a wedding date is a family and cultural matter, and we do not make claims about luck. Use the tool to convert the date your families chose, and to print both dates on the invitation.
Putting the lunar date on your invitation
Templates print the solar date. To show the lunar one too, write it into a ceremony note or a detail row — for example "Nhằm ngày 17 tháng 9 năm Đinh Mùi" — using the tool to get it right. The wording tool adds that line for you in the Vietnamese version of the text.
Still stuck?