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.
By default isLenient() is true which means that if the String in the parse() method isn't exactly in the right format it will still try to get a date from it. If setLenient(false) then the string must be in exactly the format defined by the DateFormat object.