Calculate age (accurately)

memnoch1207

I am trying to write a function that calculates the age of an individual exactly...not worried about month or days just years...every php function I have tried to use only calculates back to 1970...therefore anyone born before 1970 would show an age of 32. I need this function to be able to calculate the age of someone born back in the early 1880's and later...I have thought of just a basic calculation like this:

function calculate_age($year)
{
	$today  = getdate();
	$tyear  = $today['year'];

$age = $tyear - $year;

return $age; 
}

but it will still be inaccuarate....any ideas???

eoghain

Well trying to use some of PHP's date functions to do the calculations will give you that problem with 1970, since 1970 is when current computer clocks have started counting from.

But why do you say that your function below returns inaccurate data?

If you pass in 1880 as the year, and $tyear gets filled with 2002, then $age should equal 2002 - 1880 or 122. I don't see anything wrong with your code or it's logic (since you don't care about month/day).

netizen

It looks accurate enough. But ...

function calculate_age($year){

 $today = date('Y');

 $age = $today - $year;

 return $age;

}

Either way with date() or getdate() you should get the current year.

memnoch1207

The code i posted above doesn't calculate the age accurately...for instance if i wanted the age of someone born on Dec. 07, 1969 it calculates the age as 33, but their actually 32...thats what i meant by not calculating it accurately.

Here is the function I wrote that calculates the age accurately if anyone is interested.
It will calculate the age for someone born in the year 1 A.D. to now.

function calculate_age($m, $d, $y)
{ 
	$now = getdate();
	$nmonth = $now['month'];
	$nday   = $now['mday'];
	$nyear  = $now['year'];

if ($nmonth < $m OR $nmonth = $m AND $nday < $d) {
	$age = $nyear - $y - 1;
} else {
    $age = $nyear - $y;
}

return $age; 
}

eoghain

Ofcourse it doesn't calculate accurately, but in your original post you stated:

...not worried about month or days just years...

Which would give yue improper (off by 1) ages for people depending on the month/day they were born on, and what month/day it is today.