title: Erlang: Timer - How to get seconds until expiry by the TRef?
body: <p>Is there a way in Erlang to get the number of seconds (or milliseconds) until a timer expires using the timer reference?</p>
  
  <p>Example: the code starts a timer and, after a while, I want to check how much time is left to expire.</p>
  
  <p>Thanks in advance.</p>