title: SELECT * users who are a certain age
body: <p>In the <code>users</code> table I have a field called <code>dob</code> which stores the date of birth of the user in this format:</p>
  
  <pre><code>1959-04-02
  </code></pre>
  
  <p>Anyway I would like to SELECT all users who are 18 and 19 years old. This is my query:</p>
  
  <pre><code>SELECT *
  FROM `users`
  WHERE dob BETWEEN '1993-10-30' AND '1994-10-30'
  </code></pre>
  
  <p>But it only seems to select mostly 18 year olds and some (but not all) 19 year olds. I have a bunch of test users in the db and the number of 18 and 19 year olds are equal. Yet this query yields about 90% 18 year olds and about 10% 19 year olds. Why?</p>