MySQL Datestamp Comparison without mktime()

[bengoerz]

I recently needed to display a user's age by calculating from a MySQL datestamp. Because my users could be older than a unix timestamp can function, using mktime() was not an option. I did not find a quick solution online, so I created the following:

 

// Convert date of birth to age

// Pull Date of Birth from MySQL
// For demonstration, this is defaulted to Dec 7, 1941
$dob = "1941-12-07";

// Create current datestamp in YYYY-MM-DD format
$today = date("Y-m-d", time());

// Subtract birth year from current year, -1 for partial first year
$age = substr($today, 0, 4) - substr($dob, 0, 4) - 1;

// If birthday this year has past, add 1 to age
$thisMMDD = (substr($today, 5, 2).substr($today, 8, 2));
$birthMMDD = (substr($dob, 5, 2).substr($dob, 8, 2));
if($thisMMDD > $birthMMDD){
			$age++;
		}
// Output age
echo $age;

 

This works, but would anyone like to offer a more elegant solution?

[Barand]

If you formatted the dates with 'Ymd' instead of 'Y-m-d' you only need 1 substr() for 'mmdd'

 

Also you can do it with timestamp values

<?php
$dob = strtotime("1941-12-07");       // later versions of php handle negative timestamps
$age = date('Y') - date('Y', $dob) - 1;
if (date('md') > date('md', $dob) ) $age++;
echo $age;

?>

--> 65

[bengoerz]

Thanks for the great solution. Unfortunately, it doesn't do me any good because I am on a little earlier version of PHP. But I'm sure others can use it.

 

From the date() manual:

The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 GMT to Tue, 19 Jan 2038 03:14:07 GMT. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer). However, before PHP 5.1.0 this range was limited from 01-01-1970 to 19-01-2038 on some systems (e.g. Windows).