Time entries on previous year (closed time period) are been processed and picked up by the Posting jobs and data is available in the WIP table with current entry date.
Release : Any
Component : CA PPM TIME MANAGEMENT
If the timesheets were Approved before the period was Closed, they will be posted, and also create a transaction and that can be also posted to WIP.
If the transaction was in Invalid Transactions and the conditions that were stopping it to post clear, the transaction will also be posted.
So the question is how to avoid that in future - we suggest to check what was different this time with regards to your usual process and address it. In this occurrence, a resource department was changed, which triggered the Invalid transactions to post. Check the resource and project Audit trail to see what changed.
We also recommend reviewing the timesheets for past periods before closing the time period. Ideally we suggest to post all timesheets and financials before closing a time period.