title: How to work around Out of bounds nanosecond
body: <pre><code> LastLogin                         LastPurchased              
  2018-08-21 00:28:04.081677         0001-01-01 00:00:00
  2018-08-21 00:28:58.209522         2018-08-20 00:28:58.209522    
  </code></pre>
  
  <p>I need difference in days <code>(df[LastLogin] - df['LastPurchased']).dt.days</code> but there are some <code>'0001-01-01 00:00:00'</code> in <code>LastPurchased</code>. Anything I try to do to change <code>1-01-01</code> to a date within the Panda bounds results in <code>Out of bounds nanosecond timestamp: 1-01-01 00:00:00</code>. Is there any other ways?</p>
  
  <pre><code>     LastLogin                         LastPurchased              Days
  2018-08-21 00:28:04.081677         1999-01-01 00:00:00            6935
  2018-08-21 00:28:58.209522         2018-08-20 00:28:58.209522      1
  </code></pre>