I want to change the inventory valuation for all the inventory to 01.08.2020

A jolly good day to you, @mohammed-shafiq-. You've come to the right place for an answer.

I'm here to ensure that you can change the inventory valuation date to 01.08.2020 transparently. As such, the data will be up-to-date in your reports. Glad to provide the detailed steps to achieve your goal. 

Here's how: 

1. Go to the Sales tab on the left side. 
2. Select Product and services. 
3. Click the small drop-down, then choose Inventory in the Type field and pick Apply.
4. Hit Edit perpendicular to the item. 
5. Click the Starting value hyperlink and modify the As of Date to 01.08.2020.
6. Tap Save and close. 
7. Repeat the steps for all inventory you want to update. 

In addition, check out these articles below to see your best sellers products, stocks, still in order, and other related topics: 

• Use reports to see your sales and inventory status
• Change product and service item types in QuickBooks Online

Don't hesitate to leave a comment below if you have follow-up questions about your inventory. I'm always ready to work with you again to address QuickBooks-related issues. Keep safe, mohammed-shafiq-.