Hi
Do you mean you get the material availability date (MBDAT) on a weekend? Shipping calendar will not restrict confirmation on a weekend. It will restrict the actual shipping. Can you post a screenshot of all the dates which are determined from Sales order? It will be easier to troubleshoot.
Also, you mentioned condition records on Mon-Fri in APO? What exactly do you mean by condition records? Are you talking about scheduling condition records? Please elaborate more.
Parth Soneji