Call Function in FOX - 'DATE_TO_PERIOD_CONVERT'

Question

Hi,
I have added the FM in 'DATE_TO_PERIOD_CONVERT' in RSPLF_FDIR.
There are 2 Date fields which the user enters based on which I need to populate another field- 'No. of Months'.
I need to convert the dates into months before I calculate the number of months.(difference of the two periods).
When I tried to pass the parameters to the FM, Im gettin an error as below:
Types of parameter I_DATE () and variable CHA_ZSTCTDT(D) are inconsistent
When I checked the domain of both the fields, both are of the same type DATS of length 8.
Im not able to figure out what went wrong..
Sample Code:
DATA CHA_ZSTCTDT TYPE ZSTCTDT.
DATA CHA_ZEDCTDT TYPE ZEDCTDT.
DATA CHA_FISCPER3 TYPE 0FISCPER3.
DATA CHA_FISCYEAR TYPE 0FISCYEAR.
CALL FUNCTION 'DATE_TO_PERIOD_CONVERT'
EXPORTING
            I_DATE                =    CHA_ZSTCTDT
            I_MONMIT            = 00
            I_PERIV               = 'K4'
         IMPORTING
           E_BUPER               = CHA_FISCPER3
           E_GJAHR              = CHA_FISCYEAR .
Rgds
Shyam

Answer 1

When I defined as String:
Types of parameter I_DATE () and variable CHA_ZSTCTDT(C) are inconsistent.
But again Bindu,
as per Marcs document on FOX:
Restriction on types for parameters
– F, I, D, or STRING
– Types of characteristics and attributes
– No structures or tables..
I tried all those, but stills ame error
Rgds
Shyam