Some questions can only be answered by counting days: how old is someone exactly, in years, months and days — or how many days remain until a deadline, wedding, exam or launch? The age calculator turns any birthdate into a precise age, while the D-Day calculator counts up or down between any two dates you choose.
Both calculators handle leap years and different month lengths correctly, and the result updates the moment you change a date. Nothing you enter is stored or sent to a server; the calculation happens instantly, right in your browser, with no rounding errors or manual counting on a calendar.
Enter one birthdate to get an exact age in years, months and days as of today.
D-Day calculator
Enter two dates to count the days between them, forward or backward — for a deadline, wedding or anniversary.
Age chart
A lookup table by birth year, not a single date — useful when you only know someone's birth year, or want to check many years, the Japanese era and the zodiac animal at once.
Lunar calendar converter
Converts between the solar and lunar calendar for holidays and birthdays still tracked by the lunar date.
Frequently asked questions
What's the difference between the age calculator and D-Day calculator?
The age calculator takes one birthdate and returns your exact age today. The D-Day calculator takes any two dates and counts the days between them, whether that's counting down to a future date or up from a past one.
How is the age chart different from the age calculator?
The age calculator needs your exact birthdate. The age chart instead lists every birth year at once, so you can look up an age when you only know the year, or check many people's ages, era year and zodiac animal side by side.
Which country's calendar does the lunar converter use?
It uses the same astronomical calculation published for Vietnam's official lunar calendar, anchored to Vietnam time (UTC+7). Because Vietnam, China and Korea share the same lunisolar calendar system, the resulting date matches the Chinese and Korean lunar calendar for almost all days of the year.