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Michael Lintz

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Calculate Age

01.28.2006

| 114717 views |

        With this function you can calculate the age of a person

Example:
echo "Age is: " . birthday ("1984-07-05");

Result will be (23 Feb 2005) = "Age is: 20"

<?php

  //calculate years of age (input string: YYYY-MM-DD)
  function birthday ($birthday){
    list($year,$month,$day) = explode("-",$birthday);
    $year_diff  = date("Y") - $year;
    $month_diff = date("m") - $month;
    $day_diff   = date("d") - $day;
    if ($day_diff < 0 || $month_diff < 0)
      $year_diff--;
    return $year_diff;
  }

?>

Tags:

age
date
php

Comments

Snippets Manager replied on Wed, 2011/06/08 - 1:09am

This could be wrong (I haven't put it through it's proper paces yet) but for those that want something simple like the first post that actually calculates properly you should try this (I have very little experience programming so it is very fundamental):


function get_age($Birthdate){
        if (empty($Birthdate)){
        	 return false;
        }	
     
        list($BirthYear,$BirthMonth,$BirthDay) = explode("-", $Birthdate);
        $YearDiff = date("Y") - $BirthYear;
        $MonthDiff = date("m") - $BirthMonth;
        $DayDiff = date("d") - $BirthDay;
     
        // If the birthday has not occured this year
        if ($MonthDiff == 0){
            if($DayDiff < 0)
          $YearDiff--;
        }

        if ($MonthDiff < 0){
                $YearDiff--;
        }
        return $YearDiff;
}

Snippets Manager replied on Fri, 2011/01/14 - 10:41am

ups... last post was not formatted.


public static function calculateFriendlyAge($unformattedDate) {
	// array that hold the year, month and days text
	$friendlyAgeText = array();

	// internal class for get the date
	$oMD = new MagicDate($unformattedDate);
	$yearDiff = date("Y") - $oMD->getYear();
	$monthDiff = date("m") - $oMD->getMonth();
	$dayDiff = date("d") - $oMD->getDay();

	if ($monthDiff < 0) { // trick: now is January, and the birthdate on December
		$yearDiff--;
		$monthDiff += 12;
	}
	if ($dayDiff < 0) { // trick: now is 20, and the birthdate is past Month, on 25.
		$monthDiff--;
		$dayDiff += 30; // dirty: no support for 28-29 days on february, 31 days on some months
	}

	// the age is already numeric, now convert to friendly text
	switch ($yearDiff):
		case 0:
			break;
		case 1:
			$friendlyAgeText[] = "1 year";
			break;
		default:
			$friendlyAgeText[] = $yearDiff . " years";
			break;
	endswitch;
	if ($yearDiff <= 4) { // support "with months" for child born 4 years ago
		switch ($monthDiff):
			case 0: break;
			case 1:
				$friendlyAgeText[] = "1 month";
				break;
			default:
				$friendlyAgeText[] = $monthDiff . " months";
				break;
		endswitch;
		if ($yearDiff == 0 && $monthDiff <= 3 && $dayDiff > 0) { // support "with days" for baby born 3 months ago
			$friendlyAgeText[] = $dayDiff . " days";
		}
	}

	return join(" and ", $friendlyAgeText);
}

Snippets Manager replied on Fri, 2011/01/14 - 10:41am

/* convert age in friendly text. Support "and days" for babies born 3 months ago. And, support for "and x months" for children born 4 years ago. eg: - 3 days - 1 month and 15 days - 6 months - 1 year and 4 months - 5 years */ public static function calculateFriendlyAge($unformattedDate) { // array that hold the year, month and days text $friendlyAgeText = array(); // internal class for get the date $oMD = new MagicDate($unformattedDate); $yearDiff = date("Y") - $oMD->getYear(); $monthDiff = date("m") - $oMD->getMonth(); $dayDiff = date("d") - $oMD->getDay(); if ($monthDiff < 0) { // trick: now is January, and the birthdate on December $yearDiff--; $monthDiff += 12; } if ($dayDiff < 0) { // trick: now is 20, and the birthdate is past Month, on 25. $monthDiff--; $dayDiff += 30; // dirty: no support for 28-29 days on february, 31 days on some months } // the age is already numeric, now convert to friendly text switch ($yearDiff): case 0: break; case 1: $friendlyAgeText[] = "1 year"; break; default: $friendlyAgeText[] = $yearDiff . " years"; break; endswitch; if ($yearDiff <= 4) { // support "with months" for child born 4 years ago switch ($monthDiff): case 0: break; case 1: $friendlyAgeText[] = "1 month"; break; default: $friendlyAgeText[] = $monthDiff . " months"; break; endswitch; if ($yearDiff == 0 && $monthDiff <= 3 && $dayDiff > 0) { // support "with days" for baby born 3 months ago $friendlyAgeText[] = $dayDiff . " days"; } } return join(" and ", $friendlyAgeText); }

Snippets Manager replied on Thu, 2012/02/16 - 4:59pm


$birth = strtotime($data['year'].'-'.$data['month'].'-'.$data['day']);
$age_in_seconds = time() - $birth;
$age = floor($age_in_seconds / 31556926); // 31 556 926 seconds in year

Snippets Manager replied on Wed, 2009/09/23 - 6:32am

calamus77's version with tight ternary operators FTW!

Snippets Manager replied on Fri, 2008/12/26 - 10:12pm

Of course, the version above only lasted until the New Year. This new version now copes with determining age in months across the Dec-Jan divide. It also arbitrarily tightens up the accuracy 'within' a month.


function GetAge($DOB, $DOD) {

	// Get current date
	$CD = date("Y-n-d");
	list($cY,$cm,$cd) = explode("-",$CD);
	
	// Get date of birth
	list($bY,$bm,$bd) = explode("-",$DOB);
	// is there a date of death?
	
	if ($DOD!="" && $DOD != "0000-00-00") {

	// Animal is dead
		list($dY,$dm,$dd) = explode("-",$DOD);
			if ($bY == $dY) {
     			$months = $dm - $bm;
	     		if ($months == 0 || $months > 1) {
	     			return "$months months";
	     		} else
	    			return "$months month";
			} else 
   				$years = ( $dm.$dd < $bm.$bd ? $dY-$bY-1 : $dY-$bY );
	     		if ($years == 0 || $years > 1) {
	     			return "$years years";
				} else { 
	    			return "$years year";
				}

	} else {

	// Animal is alive
		if ($bY != "" && $bY != "0000") {	

	     	if ($bY == $cY) {
				// Birth year is current year
	     		$months = $cm - $bm;
		     		if ($months == 0 || $months > 1) {
		     			return "$months months";
		     		} else 
		    			return "$months month";
			} else if ($cY - $bY == 1 && $cm - $bm < 12) {
				// Born within 12 months, either side of 01 Jan
					//Determine days and therefore proportion of month
					if ($cd - $bd > 0) {
						$xm = 0;
					} else { 
						$xm = 1;
					}
				$months = 12 - $bm + $cm - $xm;
		     		if ($months == 0 || $months > 1) {
		     			return "$months months";
		     		} else { 
		    			return "$months month";
					}
			} 

			// Animal older than 12 months, return in years
			$years = (date("md") < $bm.$bd ? date("Y")-$bY-1 : date("Y")-$bY );
     		if ($years == 0 || $years > 1) {
     			return "$years years";
			} else { 
    			return "$years year";
			}
			
		} else	
    	return "No Date of Birth!";
	}	
}

Snippets Manager replied on Fri, 2008/12/26 - 10:12pm

I have modified this code for my cattle stud database. It covers the 'infants' and gives the age at death of those that have died.


function GetAge($DOB, $DOD) {
	list($bY,$bm,$bd) = explode("-",$DOB);
	if ($DOD!="" && $DOD != "0000-00-00") {
	// Animal is dead
		list($dY,$dm,$dd) = explode("-",$DOD);
			if ($bY == $dY) {
     			$months = $dm - $bm;
	     		if ($months == 0 || $months > 1) {
	     			return "$months months";
	     		} else
	    			return "$months month";
			} else 
   				return( $dm.$dd < $bm.$bd ? $dY-$bY-1 : $dY-$bY );
	} else
	// Animal is alive
	if ($bY != "" && $bY != "0000") {	
     	if ($bY == date("Y")) {
     		$months = date('m') - $bm;
     		if ($months == 0 || $months > 1) {
     			return "$months months";
     		} else 
    			return "$months month";
		} else
			return( date("md") < $bm.$bd ? date("Y")-$bY-1 : date("Y")-$bY );
	} else	
    	return "No Date of Birth!";
}

Snippets Manager replied on Sun, 2008/08/17 - 10:03pm

There was a bug in my code that didn't anticipate infants. Here's the corrected version:


function getAge( $p_strDate, $e_strDate ) {
		list($Y,$m,$d) = explode("-",$p_strDate);
		if ($Y != "" && $Y != "0000") {	
			if ($Y == date("Y")) {
				$months = date('m') - $m;
				if ($months == 0 || $months > 1)
					return "$months months old";
				else
					return "$months month old";
			} else { 
				if ($e_strDate!="" && $e_strDate != "0000-00-00") {
					list($eY,$em,$ed) = explode("-",$e_strDate);
					return( $em.$ed < $m.$d ? $eY-$Y-1 : $eY-$Y );
				} else
					return( date("md") < $m.$d ? date("Y")-$Y-1 : date("Y")-$Y );
			}
		}
		else
			return "???";
	}

Snippets Manager replied on Sun, 2008/08/17 - 10:03pm

I've upgraded your getAge function to include a death date and account for a null date.


function getAge( $p_strDate, $e_strDate ) {
	list($Y,$m,$d) = explode("-",$p_strDate);
	if ($Y != date("Y") && $Y != "" && $Y != "0000") {	
		if ($e_strDate!="" && $e_strDate != "0000-00-00") {
			list($eY,$em,$ed) = explode("-",$e_strDate);
			return( $em.$ed < $m.$d ? $eY-$Y-1 : $eY-$Y );
		} else
			return( date("md") < $m.$d ? date("Y")-$Y-1 : date("Y")-$Y );
	}
	else
		return "???";
}

Robbie

Snippets Manager replied on Tue, 2008/04/01 - 2:22pm

A much easier way to do this is just to compare date("md") against concatenated variables: ($month.$day):


function getAge( $p_strDate ) {
    list($Y,$m,$d)    = explode("-",$p_strDate);
    $years            = date("Y") - $Y;
    
    if( date("md") < $m.$d ) { $years--; }
    return $years;
}

I posted the above because many people don't like ?: syntax...but personally, I like getting things compact, so I would actually do the function like so:


function getAge( $p_strDate ) {
    list($Y,$m,$d)    = explode("-",$p_strDate);
    return( date("md") < $m.$d ? date("Y")-$Y-1 : date("Y")-$Y );
}

Snippets Manager replied on Sun, 2006/07/02 - 7:34pm

I think there is a little bug in the code in that the date checking is not thorough enough, This extra line checks against the day only if the month matches and seems to always give the right answer,


 function birthday ($birthday)
  {
    list($year,$month,$day) = explode("-",$birthday);
    $year_diff  = date("Y") - $year;
    $month_diff = date("m") - $month;
    $day_diff   = date("d") - $day;
    if ($month_diff < 0) $year_diff--;
    elseif (($month_diff==0) && ($day_diff < 0)) $year_diff--;
    return $year_diff;
  }
    echo birthday("1980-07-02");
  }

also, as an aside, I am very new to php programming and have not posted before, so if I am stepping on peoples toes, I am very sorry :)