title: Convert a 12 hour time format to 24 hour time format (keeping record of the day) in python
body: <p>Following is a list in python which contains a list of time for a train with each index as a stoppage for the train</p>
  
  <pre><code>Train_arrival_time = ['Source', '09:30 PM', '09:56 PM', '11:23 PM', '12:01 AM', '12:12 AM', '12:44 AM', '01:55 AM', '03:18 AM', '04:58 AM', '06:18 AM', '06:33 AM', '07:23 AM', '08:45 AM', '09:14 AM', '10:17 AM', '10:59 AM', '12:15 PM', '01:30 PM', '01:49 PM', '02:55 PM', '03:16 PM', '03:58 PM', '05:15 PM', '05:38 PM', '06:45 PM', '07:20 PM', '08:07 PM', '08:38 PM', '09:25 PM', '11:28 PM', '12:50 AM', '01:21 AM', '01:53 AM', '02:45 AM', '02:57 AM', '03:45 AM', '05:20 AM', '06:00 AM', '06:30 AM']
  </code></pre>
  
  <p>As evident from the list, this train runs for three consecutive days (<code>source</code> is the starting station). I am trying to get the time difference between two stations , and since using <strong>12-hour format</strong> will create chaos i tried using the following script to convert the whole list to <strong>24-hour format</strong></p>
  
  <pre><code>from datetime import *
  t12 = '09:35 PM'
  t24 =  datetime.strptime(t12, '%I:%M %p')
  </code></pre>
  
  <p>which is giving</p>
  
  <pre><code>1900-01-01 21:35:00
  </code></pre>
  
  <p>as an output. Is there any way to avoid getting the UTC date?
  Additionally, I am stuck on how shall I get the time difference between two stations on different days; viz, <strong>09:30PM (day 1) and 12:15PM (day2)</strong></p>