check these links .. it might help
Code: 
http://www.hashemian.com/tools/javascript-countdown.html

http://www.askdavetaylor.com/how_do_i_create_a_javascript_countdown_timer_on_my_web_page.html
im9ure Reviewed by im9ure on . Help with Java Script I have the following java script for dispalying how long our gaming clan has been around. What it does is count downs the days until a sertain date, which is our Anniversary. What I would like to do is modify this code to update the year ("August 18, 2010") and restart the count and update the number of years or the Anniversary with out having to do it manually . <SCRIPT LANGUAGE = "JavaScript"> var now = new Date(); // set this value to the countdown date. var then = new Date("August 18, Rating: 5