JavaScript YMD Age Calculator

Calculates age from date and date of birth in year/month/day format.

Assumes New Year on Jan. 1.

This version can use two different computation methods:

  1. 30-day fixed-length months (the "8870" system is a variant of this)
  2. Calendar-length months

Please see my explanation of birthdate calculation methods.

Also note that the fixed-length month calculation does not give the exact time elapsed!

This JavaScript utility uses tables, the forms interface, and of course JavaScript. JavaScript is supported by most browsers today, though some very old browsers, such as Netscape 1.0, don't.

Please report any problems with the mail link below, but first make sure you're not just reading something wrong.

Calendar:

Month Length:

Enter date from which to calculate age and date of birth:

YearMonthDay
Date:
YearMonthDay
Birthdate:




Age: years months days

To perform your calculation, click on this button: .

Related pages:

This has been yet another web page by Ben Buckner.