How to calculate with dates in a stored procedure ?

This one works fine:
pbxWAIT_TIME_LAST =
CURRENT_TIMESTAMP - odCREATED_AT ;

On this one
pbxSTATUS_COUNTDOWN =
CURRENT_DATE - odDELIVERY_DATE ;

i get an
ISC-Error 335544606 - expression eval not supported

pbxXXXXX vars are defined as Integer
odCREATED_AT is defined as timestamp
odDELIVERY_DATE is defined as date

FB Dialect 3

Any hints please ???

=> I just found it by my own that
you can not use CURRENT_DATE
but CURRENT_TIMESTAMP will do the job anyway ...

Hi,you can try

pbxSTATUS_COUNTDOWN =cast (CURRENT_DATE - odDELIVERY_DATE as integer) ;