title: Get time from a date/time string
body: <p>I have a date value stored in a variable. I need to extract the time part of the value in to a separate variable and then add/subtract time from it.</p>
  
  <p>The date variable is set with date('YmdHis'), giving (for example) 20110805124000 for August 5th 2011, 12:40:00 </p>
  
  <p>From the value 20110805124000 (which is stored in the variable $fulltime), I need to store the time only in the format 12:40 (so ignoring the year, month, day and seconds and adding the colon between the hour and minute) in a variable called $shorttime. I then need to add a number of hours to that time (so for example +3 hours would change the value in the $shorttime variable to 15:40). The number of hours I need to add is stored in a variable called $addtime, and this value could be a negative number.</p>
  
  <p>Is this easily doable? Could anyone help?</p>
  
  <p>Thanks :)</p>