Thanks Ruben! Helpful stuff - you really are a bit of an SPSS guru ;)
If you'd like to RECODE a date variable, you could do so by recoding the underlying numbers which you'll see after running something like
However, the more likely solution for this is using DATE.DMY combined with IF as in
IF(mydate > DATE.DMY(1,1,2018)) outputvariable = ....
For recoding date ranges, try IF with RANGE with DATE.DMY.
Hope that helps!
14th October 1582 is the exact timepoint that SPSS uses to calculate it's date in seconds from. Just in case anyone wants to recode a date variable using syntax. You will need this date.