Date problem

HI I have to compare 2 dates. From the file the format is 6 00 S, yymmdd.

I need to comopare this date to the current date, less 60 days. So I take
the system date, and I want to subtract 60 days from it. I put the system
date into a field yymmdd.

I set my result field as:

Dact_Date         s               d

then :

 c     yymmdd        Subdur    60:*Days      act_Date

but I am getting an error in compile:

RNF7052 30      1 Factor 1 and Factor 2 are not the same type; the
                  specification is ignored.

which is correct, in fact, act_date is considered as:

          ACT_DATE          D(10*USA/)

my question is, how to have act_date be the same type as a simple numeric
field?

Thanks,
Steve