title: transform timestamp (Seconds sins 1.1.1904) from NetCDF file
body: <p>even there are several posts concerning NetCDF files and timestamp conversion I draw a blank today.</p>
  <p>I
  read in a NetCDF data set (version 3), and after I call variables information:</p>
  <pre><code># Load required Python packages
  import netCDF4 as nc
  import matplotlib.pyplot as plt
  from datetime import datetime, timedelta
  import pandas as pd
  
  #read in a NetCDF data set
  ds = nc.Dataset(fn)
  
  # call time variable information
  print(ds['time'])
  </code></pre>
  <p>As answer I get:</p>
  <pre><code>&lt;class 'netCDF4._netCDF4.Variable'&gt;
  float64 time(time)
      units: seconds since 1904-01-01 00:00:00.000 00:00
      long_name: time UTC
      axis: T
  unlimited dimensions: time
  current shape = (5760,)
  filling on, default _FillValue of 9.969209968386869e+36 used
  </code></pre>
  <p>Now I would like to transform the seconds since 1.1.1904 time stamp into a DD.MM.YYYY HH:MM:SS.sss format. (by the way: why is there a second 00:00 information included after the time stamp?)</p>
  <p>(1) I tried:</p>
  <pre><code>t = ds['time'][:]
  dtime = []
  dtime = (pd.to_datetime(t, format='%d.%m.%Y %H:%M:%S.micros') - datetime(1904, 1, 1)).total_seconds()
  </code></pre>
  <p>And I get the error:
  pandas_libs\tslibs\strptime.pyx in pandas._libs.tslibs.strptime.array_strptime()
  time data '3730320000' does not match format '%d.%m.%Y %H:%M:%S' (match)</p>
  <p>(2) I tried:</p>
  <pre><code>d = datetime.strptime(&quot;01-01-1904&quot;, &quot;%m-%d-%Y&quot;)
  dt = d + timedelta(seconds=(t))
  </code></pre>
  <p>I get the
  TypeError: unsupported type for timedelta seconds component: MaskedArray</p>
  <p>(3) I tried</p>
  <pre><code>d = datetime.strptime(&quot;%m-%d-%Y&quot;, &quot;01-01-1904&quot;)
  dt = d + timedelta(seconds=(ds['time']))
  </code></pre>
  <p>And I get the answer:
  unsupported type for timedelta seconds component: netCDF4._netCDF4.Variable</p>
  <p>Has somebody a clearer view on the solution than I have at the moment?</p>
  <p>Thanks,
  Swawa</p>