Selections conditions at the Infopackage

Hi,

My Requirement is to load data for the selection conditions of Current month+12 periods and Current Month-24 periods for the Calmonth characteristic by writing a routine at the infopackage level.

Is there any standared function module for caluclating the year and period using the system date.

If I use 'DATE_TO_PERIOD_CONVERT' then this would give me the year and period but that needs my fiscal variant.

Could some pne help me with this.

Regards,

Vamsi