Calculate Birth date from the Age

[Simplyput]

Hello All

I have found too many examples and explainations on how to do this if I had the birthday. However, I do not. All I have is the AGE. I was thinking of contructing the birth day logically like this.

Make a function that takes the timestamp - Age and then update a month, day, and year field. I know this will not be accurate but I need to populate these fields as a temporary profile for the member.

SELECT

ID

UNIX_TIMESTAMP(CreationDate) AS CreationDate,

AccountType,

username,

(YEAR(NOW()) - Age(birthdate)) - (RIGHT(NOW(),5) < RIGHT(DATE(birthdate),5)) AS age

FROM tablea

WHERE ID = '".x"'

LIMIT 1

;

I know this may make no since but I am trying to get this data into a script that is encoded. The code prevents me from inserting the birthday from the registration. Any help will be greatly appreciative.

[NogDog]

I'm a little unclear as to what fields are what, but if we assume that birthday is a DATE type column and age is an INTEGER type for number of years, then you could simply update the whole table with:

UPDATE `tablea` 
SET `birthdate` = DATE_SUB(`CreationDate`, INTERVAL `age` YEAR) 
WHERE `birthdate` IS NULL

[bpat1434]

Well, here's a simple PHP function to do it:

function birthdayFromAge($years=null, $months=null, $days=null)
{
	if($years===null || $months===null || $days===null)
		return false;

$date['month'] = '';
$date['day'] = '';
$date['year'] = '';

$date['year'] = date('Y')-$years;

$month = date('n')-$months;
if($month < 1)
{
	$month += 12;
}
$date['month'] = $month;

$day = date('j')-$days;
if($day < 1)
{
	$last_month = (date('m')-1 < 1) ? date('m')+11 : date('m')-1;
	$last_year = ($last_month > date('m')) ? date('Y')-1 : date('Y');
	$last_month_max = date('t', mktime(0,0,0, $last_month, 1, $last_year));

	$day += $last_month_max;
}
$date['day'] = $day;

return $date;
}

$date = birthdayFromAge(23, 9, 10);
echo '23 years, 9 months, 10 days: ' . $date['month'] . ' / ' . $date['day'] . ' / ' . $date['year'] . '<br />';

$date = birthdayFromAge(15, 0, 18);
echo '15 years, 0 months, 18 days: ' . $date['month'] . ' / ' . $date['day'] . ' / ' . $date['year'] . '<br />';

EDIT: Bah!! Foiled again!! Stupid me took time to "bug test" my function 🙁