title: Convert date and time to time stamp
body: <p>I have a text file ,want to open in python and take the date and time (in header) then change it to seconds (timestamp). but result is not the same as online websites. 
  Code:</p>
  
  <pre><code>with open('sample for north - Kopie.txt', "r") as f:
      content = f.readlines()
  
      for x in content :
          day = float (content [0][:2])
          month = float (content [0][3:5])
          year = float (content [0][6:10])
          hour = float (content [0][10:13])
          minn = float (content [0][14:16])
          second = float (content [0][17:19])
          time = float ((((year-1970)*31556926)+((month-1)*2629743)+((day-1)*86400)+((hour)*3600)+((minn)*60)+second))
  </code></pre>
  
  <p>for <em>13.07.2015 09:38:17</em> result of program is <em>1436911625</em> but result of websites are <em>1436780297</em>.</p>