title: Time difference in C#, 3-digit-format minutes
body: <p>I have a problem calculating difference between two timestamps, when minutes are represented with 3 digits, e.g. 180:22 = 180 minutes and 22 seconds.</p>
  
  <p>So, can you help me how can I get difference between timestamps like:</p>
  
  <p>180:22 and 122:11</p>
  
  <p>or </p>
  
  <p>232:21 and 31:34</p>
  
  <p>etc.</p>
  
  <p>UPDATE: I need to get difference between two times, defined as strings. What makes a problem is that minutes in those strings (times) are larger than 60, and they are over the limit. So I need to know how to find difference like in above examples (180:22 and 122:11, and 232:21 and 31:34)</p>