When did God's workmanship take place?

The context of Ephesians 2 suggests that God's workmanship refers to His eternal decree and creative act of salvation, which began before the foundation of the world. Ephesians 1:4 states that God chose us in Him, indicating that our salvation and His handiwork were predetermined according to His divine purpose. This signifies that our good works are not an afterthought but are intricately woven into God's plan from eternity past, reflecting His sovereignty and grace in our lives as believers.