Project Capital Asset how to set the amortization start date for Cost Adjustments

Project Capital Assets are capitalized with DPIS within the first quarter of fiscal year. For initial capitalization the Capital Asset Amortization flag is set to yes. Within the third quarter we want to capitalize cost adjustments, i.e. additional cost, with that cost amortized over the remaining life of the asset. When Asset lines are generated, associated with initial Asset and transferred to Fixed Assets, the amortization start date is blank.

What determines the amortization start date for Capital Asset cost adjustments?