title: Linux Script- Date Manipulations
body: <p>I will set one date variable(Say '08-JUN-2011') and I want to do some calculations based on that date namely,<br>
  1. Have to get the first day of the given day's month.<br>
  2. Previous date of the given date's month.<br>
  3. Last day of the given date's month.</p>
  
  <p>All I know is manipulating using the current system date and time but don't know how to implement with user defined date. I need this to be achieved using Linux shell script.</p>
  
  <p>Any help will be appreciated.</p>
  
  <p>Thanks,<br>
  Karthik </p>