That is what the SO line Promise Date is for:

But I want to create 8 releases with different qtys and different promise dates.

The same item can be on multiple lines within the same SO, each line with a date / quantity.

So do this with the master order and enter 8 different lines with the same part#, different qtys and different dates?

Standard SO, but yes. That is what I was suggesting.  There may be alternatives, but that is the most straight forward approach.

If you need your picking sheets filtered by Promise Date, or lines grouped differently in the SO printouts, edit the forms / reports.

OK. Thanks, Kevin.