How do I create a dynamic query that filters on month and day?
I was able to query the date by using a where clause instead of condition.
Example, replace

 $query-&gt;condition('field_donor_date_of_birth.field_donor_date_of_birth_value', $birth_date, '=');


with

$time = format_date(time(), 'custom', 'm-d');
$query-&gt;where("DATE_FORMAT(field_donor_date_of_birth.field_donor_date_of_birth_value, '%m-%d') = '$time'");