For the record ‘substantial completion’ is a construction contract term that means the project/building can be used by the Owner for its intended use. Most public works construction contracts include a liquidated damages clause that allows the Owner to $ back-charge (penalize) the Builder for every day they are late in reaching Substantial Completion. Keep in mind that these type of damages are offset by unforeseen circumstances (severe weather, Indian bones, etc) which extend the construction contract time.
Hope that helps.