title: How to perform arithmetic function in DATE TIME in SQL
body: <p>I have four columns namely-</p>
  
  <pre><code>1. C_Date in YYYYMMDD format (varchar(255)) Eg. 20161231
  2. C_Time in 4-digit Military format (varchar(255)) Eg. 2143
  3. E_Date in YYYYMMDD format (varchar(255)) Eg. 20161230
  4. E_Time in 4-digit Military format (varchar(255)) Eg. 1600
  </code></pre>
  
  <p>I want to Calculate the time between E event and C event. How can i perform this computation with a select statement?</p>