title: Javascript RegEx: validate time
body: <p>I have a stopwatch variable that can get value in the following format:
  <code>HH:MM:SS</code> most of the time. <code>'HH'</code> can go past 24 hours - basically any valid number. </p>
  
  <p>I am not that good with this regex thingy, but was able to write something that is good for most part but fails to validate if the hour is single digit. Ex. below regex pass the time <code>1:10:09</code>, though it is invalid. valid hour part should be <code>01</code>.</p>
  
  <pre><code>//var stopWatchTime = '02:10:09'; //Valid
  //var stopWatchTime = '00:10:09'; //Valid
  //var stopWatchTime = '1234:10:09'; //Valid
  //var stopWatchTime = ':10:09'; //Invalid
  //var stopWatchTime = 'ax:10:09'; //Invalid
  var stopWatchTime = '1:10:09'; //Invalid, should be 01:10:09. 
  
  if(!stopWatchTime .match(/^\d+:\d{2}:\d{2}$/)){
      alert('invalid time- ' + stopWatchTime);
  }
  else{
      alert('valid time - ' + stopWatchTime);
  }
  </code></pre>
  
  <p>What should I change in the regex to say it should check for any number but should have 2 digits or more in hour part?</p>