Solution : https://service.sap.com/sap/support/notes/154748 (SAP Service marketplace login required)
Key words : 
form routine form upd_obj_status, form routineform upd_obj_status, time sheet data, terms time sheet, function modulefunction cn_ms_set_act_date, missing function, project system, actual dates, set automatically, set manually
Related Notes : 
       
| 591970 | CAT5: RU895 Confirmation is posted twice | 
| 155966 | Dialog box f.transfng actual dates milestones in BI |