Expenditure item date is not within the active dates of the task

 How to charge time cards from OTL to Projects of which time card dates are falling after the task end dates.

How to avoid the error "Expenditure item date is not within the active dates of the task" with out extending the task end dates.

one option is to keep task end date as blank but client does not want this way.

There are 2000 tasks in a very big WBS structure with task duration is of 2 or 3 days, we want to allow the expenditure even after the task end date with out extending the task end date.

second option is to update the task end dates through API, but this can not be done by front end users with out the data base access.