title: How can obtain age by birth date
body: <p>I want get the exact age of the following date in var <code>$birth_date</code> by php, How is it?</p>
  
  <p><code>$birth_date = 2011/12/16;</code></p>
  
  <p>$birth_date => For example, this is my birth date.</p>
  
  <p>For example output from my birth date is: <code>0 Year, 0 Month, 1 Day</code></p>