QuickTips: PHP Function: Get Age by SQL DATE

How to calculate a person's age using an SQL formatted input date

by Matt J. Whetham, October 2010

A fairly simple procedure - calculate age from an SQL formatted date (YYYY-MM-DD) - or so I thought.  In my haste to develop an application for a customer's website, rather than creating a function myself, I figured I would do a quick Google search for a prewritten function that someone perhaps may have posted.  Usually something like this will take approximately 2 minutes max to seek out, implement, and test to ensure that it works fine.

Not in this case.

To my dismay, the functions that I found all lacked a proper method of determining the age based on TODAY.  They forgot to calculate one less year if the birthday had not yet passed this year. 

So alas, here is a proper PHP function for calculating the age of someone today, using a SQL formatted input date:

 

<?php
function getAge($sqlDate) {
// Convert SQL date to individual Y/M/D variables
    list($Y,$m,$d) = explode("-",$sqlDate);
    $age = date("Y") - $Y;
    
// If the birthday has not yet come this year
    if(date("md") < $m.$d ) {
		$years--;
	}
	
    return $years;
}
?>

Then of course, to echo it out:

<?php
$date_of_birth = "1970-12-01";
echo getAge($date_of_birth);
// Returns correct age based upon today's date
?>