This wiki shows how to check the fiscal year definition for a given company code.
The Fiscal Year variant assigned to the company code indicates the fiscal period linked to the posting date.
Go to transaction code OBY6:
The fiscal year variant is assigned.
Go to transaction code GVAR to review the fiscal year definition:
The fiscal year variant can be defined as "Year-dependent" OR "Calendar year".
If the variant is defined as "Year-dependent" the corresponding periods will be defined in transaction GVAR:
This is only required for a year dependent variant.
See section Fiscal Year Variant on sap.help.com