leap year issue

Requirement :

In oracle service contracts, we have many service contracts which falls in leap year (2016). Business needs a data fix to fix the leap year issue.

Scenario:

Service contracts,

start date : 01-jan-2016

end date : 31-dec-2016

And now, business wants to add 1 day to the end date in the header , lines and sublines. Also, 1 new line has to added to the billing stream and schedule with '0' amount with 1 day duration.

We tried replicating the scenario in the application, but the problem is , all lines gets repriced. But,business doesn't want to get the new line repriced, as old lines are already invoiced.