title: How to change date in database
body: <p>In my Mysql database, i have a set of date.
  How can I increase for each and every date in my database by 3 years ?</p>
  
  <p>For example the current date is :
  2 January 2001</p>
  
  <p>I want the date to be increased by three years: 
  2 January 2004</p>