Symptom
You have created a Stock transfer Order and have maintained the Requested Delivery Date to be Midnight on a Monday (dd/mm/yy 00:00). When you perform Availability Check, the system calculates the Execution Start Date to be the Last working Day of your Site Calendar (a Friday). However, when you change the time to one minute past midnight on the same day Monday (dd/mm/yy 00:01), and perform Availability Check again, the system calculates the Execution Start Date of the same day (Monday).
Now you are wondering why the system is behaving this way and want to have an explanation. You also would like to know if there's a way to avoid this behaviour and set a time and date that is not 00:00 by default.
Environment
SAP Business ByDesign
Reproducing the Issue
- Navigate to the Outbound Logistics Control work center.
- Go to the Customer Demand view.
- Find and select the relevant Stock Transfer Order.
- Click the Edit button.
- Go to the Line Items tab, and then to the General sub-tab.
- Change the Requested Delivery Date to a Monday for example: 21.10.2019 00:00 (You can select a date of your choice, but make sure it is a Monday).
- Check Availability.
- Now navigate to the Line Items tab, and then to the Schedule Lines sub-tab.
- You can see the Execution Start Date for the above Requested Delivery Date is 18.10.2019.
- Go back to the Line Items tab, and then to the General sub-tab.
- Now Change the Requested Delivery Date to: 21.10.2019 00:01.
- Check Availability again.
- And navigate again to the Schedule Lines sub-tab.
- You can see that the system is showing the Execution Start Date of 21.10.2019.
- What a difference 1 minute can make.
Cause
During date calculation via ATP check, a value of -1 second and +1 second (known as WriteGI index) is added to the requested execution start date. When the Requested Delivery Date is on a Monday, the previous day is taken into consideration to check if its a holiday. This is done to ensure that the execution doesn't start on a holiday. However, when it is a Tuesday, the previous day will still be a working day, hence Tuesday is proposed.
This is the reason for date variation when requested date is given on a Monday midnight.
Resolution
This is the standard behavior of the system.
There is no option to default the time but you can change the time manually while creating the Stock Transfer Order, the Sales Order etc.
Keywords
Requested, Delivery, Date, Execution, Start, Date, WriteGI index, Availability, Check , KBA , AP-CR-CR , Customer Requirement , Problem