title: Time difference in years with lubridate?
body: <p>I would like to use <code>lubridate</code> to calculate age in years given their date of birth and today's date. Right now I have this:</p>
  
  <pre><code>library(lubridate)
  today&lt;-mdy(08312015)
  dob&lt;-mdy(09071982)
  today-dob
  </code></pre>
  
  <p>which gives me their age in days. </p>