title: Ruby: How to check if a string is a valid time?
body: <p>I'm pulling data from a feed that I have no control over and I need to verify if a string I'm given is a valid time.</p>
  
  <p>Most of the time I'm correctly sent something like "2:35" or "15:41" but other times it's things like "AM" or "PM" (and no numbers)...so I ultimately just need to ignore those.</p>
  
  <p>So, how can I verify if the data is a valid time?</p>