title: change date based on midnight time
body: <p>i have dataframe which contains 3 column for date and time: <strong>date</strong> ,<strong>depart time</strong> and <strong>arrive time</strong>. i want to make two columns of datetime (<strong>depart time and arrive time</strong>) using pandas so I use <strong>to_datetime</strong> function.</p>
  
  <p>since the date column based only on the depart time, there are some cases where the depart time is around 23:00 and the arrive time is after 24:00 but the date stays the same. for instance:</p>
  
  <p><strong>depart datetime: 01/12/2017 23:58:00 arrive time 01/12/2017 00:30:00</strong></p>
  
  <p>how can i write a function that will update the day to the day after if the arrive time is after midnight? (in the example  it should be arrive time 02/12/2017) </p>
  
  <p>thanks</p>