You need to use a four digit year... This is what is commonly referred to as the Y2K issue. Code has no way of knowing what you mean with two digit years.
what would you expect 12/25/99 to be? is your date always in the future. I suppose we could hand code a solution for you that would add the 20 in front of any year input so that the user could input a two digit year and it would convert to a four digit year in a premier support ticket, if that is indeed what you want or need.