Solution : https://service.sap.com/sap/support/notes/78768 (SAP Service marketplace login required)
Key words : 
additional key words co01, 'adjust basic dates' indicator, production dates/scheduled dates, order start date, order finish date, basic dates, production order, production ordercor1, process order, maintenance order
Related Notes : 
       
| 83488 | Basic dates fall on a non-working day | 
| 76620 | PM order: calendar for order start/order finish date |