If you know year, month and fiscal year variant and you want to know the first date and end date of that period, you can apply function module "PERIOD_DAY_DETERMINE" in ABAP/4 to get them.

Example

CALL FUNCTION ’PERIOD_DAY_DETERMINE’
  EXPORTING
    I_GJAHR       =     ’2006’       "Year
    I_MONAT       =     ’01’         "Month
    I_PERIV       =     ’F2’         "Fiscal Year Variant

  IMPORTING
    E_FDAY        =     FIRST_DATE
    E_LDAY        =     END_DATE
  EXCEPTIONS
    ERROR_PERIOD         =     1
    ERROR_PERIOD_VERSION =     2
    FIRSTDAY_NOT_DEFINED =     3
    PERIOD_NOT_DEFINED   =     4
    OTHERS               =     5.