SPSS date calculations are much easier than they may seem at first. The first key to success is understanding what SPSS date variables really are. Next, choose (and possibly combine) the right date functions. This tutorial will walk you through the main ones.
For time calculations (such as the number of days between two dates) proper date variables are needed. In some cases, the digits of a numeric variable may represent year, month and day. This tutorial shows how to convert this format into an actual date variable.