You can keep track about the details of the items bought, the date of purchase and the present value of goods if a proper inventory of goods is maintained. It is actually difficult to determine the exact time when the inventory of the items is required to be listed since household items are constantly changing all the time.
Moving into your new apartment or rental apartment is the best time to make an inventory. In this kind of scenario, any loss goods can be claimed against the moving insurance company you signed up for. Be sure to also provide the description of each item in your inventory to avoid confusion in identical items.