OK - I think I understand where the problem lies.
We currently have a scheduling program and it works by assigning the start date as the beginning month (everything operates on the first day of a month) and then a duration of total months. In our model, the events represent construction equipment and the resources represent various construction projects. The external drag&drop would represent available equipment not yet scheduled.
I may take a look at the open source version. But, I really liked the your product's capability of dragging/dropping and resizing the events on the fly. I believe these features are not available in the open source version, correct?