I've got you covered, @SkeeterJohn.

While changing the start date of the inventory in bulk isn't available, you may want to edit each of them.

I understand that you have uploaded 4000 SKUs. However, editing the start date for each inventory is the only way we can consider right now. Here's how:

1. Sign in to your QuickBooks Online (QBO) account.
2. Click the Gear icon, then select Products and Services.
3. Select each inventory you want to edit.
4. Under the Action column, select Edit.
5. On the Quantity on hand section, click Starting value.
6. Select the Got it button.
7. Change the date under As of date.
8. Click Save and close.

Also, I encourage submitting feedback directly to our product engineers. They may look into this suggestion and consider adding the option in the future update. To send your feedback, you can go to the Help menu and select Send Feedback Online. Then, enter your product suggestion in the field and click Submit.

You might also want to adjust the inventory quantity on hand in the future. This article will guide you through the steps: Adjust inventory quantity on hand in QuickBooks Online.

Please know that I'm just a reply away if you need any further assistance managing your inventory in QBO. Have a good one.