This module adds the fields *Start Date* and *End Date* on sale order
lines (requied fields when the product has the *Must Have Start and
End Dates* property). You can also define a *Default Start Date* and
*Default End Date* on the sale order; when set, these dates will be used
by default on new sale order lines. Upon invoice creation, the values of
the start/end dates of the sale order line are copied to the start/end
dates of invoice lines.

This module is a technical module: it is designed to be used with other
modules such as the *sale_rental* module.
