title: Getting the index of datetime function within Numpy Python
body: <p>The code down below finds the index of <code>newdates</code> within <code>Setups</code> with the <code>init_location</code> function. Then I increment the index by one to get the next date. But I cannot add to the <code>init_location</code> function. How would I be able to do that and get the expected value?</p>
  <pre><code>import numpy as np 
  
  Setups = np.array(['2017-09-15T07:11:00.000000000', '2017-09-15T11:25:00.000000000',
                     '2017-09-15T12:11:00.000000000', '2017-12-22T03:14:00.000000000',
                     '2017-12-22T03:26:00.000000000', '2017-12-22T03:31:00.000000000',
                     '2017-12-22T03:56:00.000000000'],dtype=&quot;datetime64[ns]&quot;)
      
  
  newdates = np.array(['2017-09-15T07:11:00.000000000','2017-12-22T03:26:00.000000000'],dtype=&quot;datetime64[ns]&quot;)
  init_location= np.where(np.in1d(Setups,newdates[1]))
  print(&quot;init location: &quot;, Setups[init_location],&quot;Address right after: &quot;,Setups[init_location+1])
  </code></pre>
  <p>Output Error</p>
  <pre><code>TypeError: can only concatenate tuple (not &quot;int&quot;) to tuple
  </code></pre>
  <p>Expected Output</p>
  <pre><code>init location: 2017-12-22T03:26:00. Address right after: 2017-12-22T03:31:00.00
  </code></pre>