[SOLVED] Calculate the age of a person?

[JJohnsenDK]

Hey

 

Im trying to make a function which can calculate the age of a person from the persons birthday. Lets say im born 20. March 1980, then i want the function to  calculate how old i am today. How do i that?

[corbin]

I suggest something like

 

$bday = strtodate(); //this would have their properly formatted text birthday in it and then it would change it into a timestamp
$diff = time() - $bday;

 

Then you would have to break diff down into what ever you wanted to show.

[Jessica]

Here's the age in many measurements.

function birthdateToAge($birthdate){
$age = array();
$now = time();
$age['seconds']	= $now-$birthdate;
$age['minutes']	= floor($age['seconds']/60);
$age['hours']	= floor($age['minutes']/60);
$age['days']	= floor($age['hours']/24);
$age['years']	= floor($age['days']/365);
return $age;
}

$age = birthdateToAge(strtotime("March 20, 1980"));
print $age['years'];

 

 

[JJohnsenDK]

Thanks to both for you... jesirose very nice function, thanks

[Orio]

The mathematical way:

 

<?php

function calc_age($date)
{
$seconds = time() - strtotime($date);
$year = 60*60*24*365.25;
return floor($seconds / $year);
}

echo calc_age("March 20 1969")."<br>"; //output- 37
echo calc_age("Jan 20 1980")."<br>"; //output- 27
echo calc_age("31.5.05"); //output- 1

?>

 

Orio.

[Jessica]

Now that I think about it, due to the nature of leap years (Every 4 years except in the 100 years, except for 1000 years, etc.) It might be more accurate to do the math with the formatted dates. I guess it depends on how detailed you're trying to get.

[sasa]

I try jesirose's script

function birthdateToAge($birthdate){
$age = array();
$now = time();
$age['seconds']	= $now-$birthdate;
$age['minutes']	= floor($age['seconds']/60);
$age['hours']	= floor($age['minutes']/60);
$age['days']	= floor($age['hours']/24);
$age['years']	= floor($age['days']/365);
return $age;
}

$age = birthdateToAge(strtotime("March 20, 1980"));
print $age['years'];

it output

date born: 2003-02-05<br />

today: 2007-02-04<br />

old: 4

 

Is it OK?

 

[Orio]

Now that I think about it, due to the nature of leap years (Every 4 years except in the 100 years, except for 1000 years, etc.) It might be more accurate to do the math with the formatted dates. I guess it depends on how detailed you're trying to get.

 

So you can use the number given here by google's calculator

 

Orio.

[sasa]

i try Orio's way

<?php
function calc_age($date)
{
$seconds = time() - strtotime($date);
$year = 60*60*24*365.25;
return floor($seconds / $year);
}
echo date('Y-m-d'), "\n"; //output 2007-02-04
echo calc_age('2004-02-05'), "\n"; // output 3
echo calc_age('2005-02-05'); // output 1
?>

Is it OK?

[Jessica]

When I send that date to my function I get the correct years of:

Array

(

    [seconds] => 126184073

    [minutes] => 2103067

    [hours] => 35051

    [days] => 1460

    [years] => 3

)

 

Is your server time set to a different timezone?

[Orio]

Made a little change, now this should work:

 

<?php

function calc_age($date)
{
$seconds = time() - strtotime($date);
$year = 31556926;
return floor($seconds / $year);
}

?>

 

 

Orio.

[sasa]

3 * 365 = 1095

and 4* 365 = 1460

how years is 3?

[Jessica]

Because it's not yet been exactly three years. Those amounts are rounded down, that's what Floor does. You know by looking at it that if tomorrow is their birthday, they are not yet 4 years old. However, since we don't know the time they were born, we assume it was midnight, and when you round out the days, it turns out to be 1460. If you put in a different date such as 2003-03-05, you'll see the days go down, because it's not quite four years yet. Their age is still 3.

 

[sasa]

Made a little change, now this should work:

 

<?php

function calc_age($date)
{
$seconds = time() - strtotime($date);
$year = 31556926;
return floor($seconds / $year);
}

?>

 

 

Orio.

it stil output same results

[Jessica]

Which are? What is the problem? Both Orio's and mine work fine as far as we can tell, so you need to show what's not working.

[sasa]

Because it's not yet been exactly three years. Those amounts are rounded down, that's what Floor does. You know by looking at it that if tomorrow is their birthday, they are not yet 4 years old. However, since we don't know the time they were born, we assume it was midnight, and when you round out the days, it turns out to be 1460. If you put in a different date such as 2003-03-05, you'll see the days go down, because it's not quite four years yet. Their age is still 3.

 

no. the error is thet betwen this two date is 2004-02-29.

it cause wrong output