This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
I would work with Rene's suggested code (no need to write your own conversion when Java has the API to do it for you)! You can also then look at Calendar and Locale classes in order to get things in the correct timezone etc.