Why asset adjustment transaction date defaults to the last day of the current period

Summary:

We are migrating from peoplesoft to oracle and are loading around 90k assets in CORP book and then coping it over to tax book. Once the assets are copied to tax books, we are manually (through FBDI) updating the YTD/Reserve to match with the values from peoplesoft. This update goes into the system as an adjustment and the transaction date for this adjustment gets defaulted to the last day of the current period. Is there a way to make the adjustment date either as system/current date or 1st day of current period or may be possibly even before. The need