If any changes to the following items need to be changed on a contract that has ALREADY started, the spots (even past spots which have already aired) will go to Exceptions, because the system will either need to create a new line for the change, or because the past placement is no longer applicable.
These changes include:
Spot Length
Spot Type
Sales Group/Rotation Code/Program Code
DOA (Days on Air)
DSA (Daily Spot Allocation)
Advertiser
For example, the original line on a contract had been booked to end on a Sunday, so when a user end dates the lines to end on a Friday, those spots will be re-plotted, bumping the spots that aired earlier in the week into Exceptions.
SDS suggests that if the DOA needs to remain intact, to end date the line for the Sunday, then go into Preemption Processing and Credit out the balance of the spots for the week (if there are any). This is how to best handle mid-week end dating. The client will not see the Credits on their invoice (as long as the detailed version is not used).