title: ISO 8601 to time_t conversion in C or vice versa
body: <p>According to <a href="http://en.wikipedia.org/wiki/ISO_8601" rel="nofollow">ISO 8601</a>, time can be specified in different formats.</p>
  
  <p>My program does not know which exact ISO 8601 format will be specified. </p>
  
  <p>In this case, how can I convert it to time_t? </p>
  
  <p><code>strptime</code> requires you to specify format (which I do not know before hand in my case).</p>
  
  <p>Ultimate goal: is to compare 2 time_t timestamps.</p>
  
  <p>Edit 0: Because my goal is to compare 2 time stamps, time_t to ISO 8601 conversion will also work.</p>