can someone help explain this...

[brown2005]

function age($dob)
{

$date = strtotime($dob);

$today = strtotime(date("d/m/Y"));

echo floor(($today - $date) / 31556926);

}

age("30/03/1983");

i know floor rounds down the value but why the  / 31556926

[zq29]

Ahhh, you took that from one of my replies earlier today! There are 31,556,926 seconds in a year - A Unix timestamp is the amount of seconds since the unix epoc (1st of January 1970 ish I think).

[brown2005]

wat about leap years though?

[brown2005]

semi u there

[zq29]

Sorry, went off to do a bit of research. I'm not 100% sure on this, but I don't think it matters...

Seconds in a normal year: 3600 * 24 * 365 = 31,536,000
Seconds in a leap year: 3600 * 24 * 366 = 31,622,400
Seconds used in my function: 31,556,926 (Reported by Google - "seconds in a year")

Maybe googles answer is some kind of average that accounts for the difference caused by leap years? I really don't know to be honest.

Also, I've realised that my function won't work on all systems - negative timestamps are only supported in PHP5 and on *NIX based operating systems...

[redarrow]

//my example playing with the timestamp.

<?

function redarrow($birthday){

$d=date("d")+8;
$m=date("m")+4;
$y=date("y")+67;

$my_birth_date=date("$d$m$y");

$my_age=$y-42;

$birthday=date("y")-31;
$today_date=date("y-m-d");

if($birthday < $today_date ) {

echo " Your birthday was on the $my_birth_date I am  $my_age years old ";

}
}
redarrow($birthday);

?>

[GingerRobot]

mine:
[code]
<?php
//all values must be without leading 0. Not sure why,lol
$current_year = date("Y");
$current_month = date("n");
$current_day = date("j");
$dob_day = 21;
$dob_month = 9;
$dob_year = 1989;
$age = $current_year-$dob_year;
if($dob_month >= $current_month){
  $age--;
}

if($dob_month == $current_month && $dob_day >= $current_day){
  $age++;
}

echo $age;
?>
[/code]