Tax Book books records need a different Date Placed in Service if for a prior year Financial Book as

For example, an asset was created in the Financial book with an 11/22/2011 Date Placed In Service (DPIS). The Periodic Mass Copy created the books records in the tax books. An API updated the DPIS in the tax books to 01/01/2012. The Transaction as shown on the workbench, on the Cost History tab shows the ADDITION transaction on 11/22/2011. However, upon retirement, the system calculated Gain/Loss based on the Period Effective back to 11/22/2011 on the tax books. Why didn't it look at the 01/01/2012 DPIS? Can the Effective Date of a prior transaction be updated via an API?