I usually call

TRUNC

on each datetime individually:

CASE WHEN TRUNC({today}) - TRUNC({createddate}) > 2 THEN 1 ELSE 0 END

Calling

TRUNC

on a numeric value, like 0.75, will actually return 0, rather than 1, so it will give different results. That may be what you want, though, if you are only counting how many full days have passed since createddate.