[RESOLVED] accounting for leap years

asa_carter

This produces a result that is one day out.

What do I need to do to account for leap years and time zones or whatever is causing the problem?

$birthstamp = mktime(0, 0, 0, $month, $day, $year); 
$diff = time() - $birthstamp; 
echo $age_years = floor($diff / 31556926);

bretticus

Since you're dividing by seconds in a year, I assume you must have put in todays date x number of years ago. If that's the case, the only thing I can think of is specifiying the timezone:

date_default_timezone_set('Europe/Dublin');

If that doesn't work (not always 365 days as you've pointed out) you could just take the difference and get the how many years ahead of 1970 and then subtract 1970 (there has to be a more elegant way!)

$age_years = date("Y", $diff ) - 1970;

asa_carter

Thanks, I just tried that however it still returns a date that is one day out.

Any other suggestions or links to a calculation that provides accurate results to date calculations?

asa_carter

This seems to work just now but not sure how accurate it is:

$modDay = ($day + date("L"));
$birthstamp = mktime(0, 0, 0, $month, $modDay, $year); 
$diff = time() - $birthstamp; 
echo $age_years = floor($diff / 31556926);

NogDog

Assume that $year, $month, $day have the birth date of interest:

$today = time();
for($yr = $year, $age = -1; mktime(0,0,0,$month,$day,$yr) < $today; $yr++,$age++);
echo $age;

asa_carter

Wow!

Thanks once again NogDog.

You should publish that in your blog or somewhere searchable by google as the only thing I found by searching was a function that was about 50 lines long.

Cheers

Asa

NogDog

asa_carter;10887045 wrote:
Wow!

Thanks once again NogDog.

You should publish that in your blog or somewhere searchable by google as the only thing I found by searching was a function that was about 50 lines long.

Cheers

Asa

This site always ranks high on Google (and gets spidered often), so it will be out there soon. 🙂 (But I may stick it in my blog, too, anyway.)