The default window used has also changed. As always, you should use four-digit years whenever possible. Input and display of dates are controlled by date formats. Once read, the date is stored as the number of seconds since midnight, October 14, 1582. Thus, dates stored in SPSS data sets are not affected by year 2000 concerns.
Problems come when the dates are input or output.
Also, remember that SPSS does not know which variables are dates unless you tell it. Always use the appropriate format when reading in date values. Ideally, all data would come to you containing four-digit years. However, this is not always the case. If the data does not contain four-digit years, there must be a method used to resolve ambiguity.