Solution : https://service.sap.com/sap/support/notes/806953 (SAP Service marketplace login required)
Key words : 
call function module 'rke_generate_interface_act', shortened fiscal year reason, copa posting fiscal year, fiscal year variants, -calendar fiscal year, copa fiscal year, respective operating concern, terms copa, special periods, special period
Related Notes : 
       
| 672255 | Shortened fiscal year/changing fiscal periods |