title: Python pandas timedelta64 fillna
body: <p>I have a dataset with hundreds of columns. Some of the columns have timedelta64 type. When i use</p>
  <pre><code>fillna(0)
  </code></pre>
  <p>I got an error <code>Passing integers to fillna for timedelta64[ns] dtype is no longer supported.  To obtain the old behavior, pass pd.Timedelta(seconds=n)</code></p>
  <p>How can i fix this error?</p>