title: eeptools age_calc() error: End date must be a date after date of birth
body: <p><a href="https://i.stack.imgur.com/71XOG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/71XOG.png" alt="enter image description here"></a></p>
  
  <p>I'm using <code>age_calc()</code> from the <code>eeptools</code> package in R but am getting the error</p>
  
  <blockquote>
    <p>End date must be a date after date of birth</p>
  </blockquote>
  
  <p>Both the dob and end date are date class objects with format <code>%yyyy-%mm-%dd</code></p>
  
  <pre><code>x$age&lt;- floor(age_calc(dob = x$Date.of.Birth2, enddate = x$DisbursalDate2,
                     units = "years", precise = T))
  </code></pre>