Substantial Completion is a term that refers to the date when the main portion of the contractual agreement is complete. In Construction Management, this means that the punchlist is complete or due to be complete on this date such that the final walk through can be scheduled.
Often change orders will be issued that indicate changes to the value of the existing line items along with changes to the timeline that affect the Substantial Completion date by an increase or decrease of a number of days.
To track the Substantial Completion date in Projectmates, enter the Orig. Sub. Completion date in the Contract Details on the General tab of the contract. Then as changes are made to the timeline, create change orders with the Days Changed as either positive to push out the date or negative to make it earlier.