Thank you for your replies, our company is in one step to buy your product! Your support are great!
One more question about phGantTimePackage:
How can I show a progress by a task as it is in the Microsoft Project?
There are two possible solutions depending on your needs.
First; Implement user draw on the time item and draw it yourself, and draw the progress bar as part of the time item.
Second solution; Add another, thinner, time item in another layer. This solution will allow you users to change the progress by click and drag, but you need to move the progress bar time item when the main time item is moved.