Can i amend a previous tax return the same day as current year?

Yes, you can file them together. They will be processed separately.

To do an amendment for 2021 

Sign in to TurboTax

1. On the home screen, scroll down to Your tax returns & documents and
2. select the year (2021) 
3. Select Amend (change) return, then
4. Amend using TurboTax Online
   1. If you're told to amend your return via TurboTax Desktop, follow the steps for TurboTax CD/Download below instead.
5. On the screen OK, let's get a kickstart on your amended return, select the reason(s) you're amending and Continue.
6. When you reach Here's the info for your amended federal return, select Start next to the info you need to change.
7. Continue through the screens, make the changes you need to make, and carefully answer the remaining questions to finish amending your return.
    

Same day?

You won't be able to e-File a 2021 1040-X.

I won't be filed until the US Mail can deliver it to the IRS.

If you also mail a 2023 1040-X it should be filed separately to avoid misunderstandings.

@hiz1soldier