title: How to properly format a time as loaded from a file with numpy.genfromtxt()?
body: <p>my code:</p>
  
  <pre><code>def parsetime(v): 
      return np.datetime64( 'filename.txt',
                             datetime.datetime.strptime( v, '%H:%M' )
                             )
  
  hor = np.genfromtxt( 'filename.txt',
                        skip_header = 3,
                        usecols     = ( 1, 3, 4, 5, 6, 7, 8, 9 ),
                        converters  = { 1: parsetime }
                        )
  </code></pre>
  
  <p>Got this:</p>
  
  <blockquote>
    <p>TypeError: Invalid object for specifying NumPy datetime metadata </p>
  </blockquote>
  
  <p>Dataset:</p>
  
  <pre><code>*****************************************************************************************
   Date__(UT)__HR:MN     Obsrv-lon Obsrv-lat Solar-lon Solar-lat      phi  PAB-LON  PAB-LAT
  *****************************************************************************************
   2017-Feb-11 00:00  m    4.87809   1.86737   5.04236   0.27627   1.5995 142.1040  -0.7968
   2017-Feb-11 00:05  m    4.86722   1.86711   5.00023   0.27616   1.5965 142.1233  -0.7972
   2017-Feb-11 00:10  m    4.85641   1.86690   4.95810   0.27604   1.5941 142.1426  -0.7975
   2017-Feb-11 00:11  m    4.85426   1.86686   4.94968   0.27602   1.5937 142.1464  -0.7976
   2017-Feb-11 00:12  m    4.85211   1.86682   4.94125   0.27599   1.5933 142.1503  -0.7977
   2017-Feb-11 00:13  m    4.84997   1.86679   4.93283   0.27597   1.5930 142.1541  -0.7977
   2017-Feb-11 00:14  m    4.84782   1.86676   4.92440   0.27595   1.5926 142.1580  -0.7978
  </code></pre>