It would definitely be within 30 days, but it would be of next year.
So would this successfully by pass the wash sale rule?
No, that's the whole point of the wash sale rule, to keep people from realizing a loss at the end of the year for tax purposes without significantly changing their position.
This assumes that you sold at a loss - if you sold for a gain, you would owe the tax when you file your 2021 taxes, but would raise your tax basis, reducing the amount of tax you'd pay later, which may be a wise strategy in some circumstances.
No, this would not avoid the wash sale rule.
The criteria is not "+/- 30 days within a year"
In general, regarding taxes...
If you think you have found a 'trick' all by yourself, maybe you should recheck everything carefully. Then look for additional laws that govern this type of thing.
Then, if it still seems like a good idea, it is okay to ask here - but maybe spend a couple hundred to consult a professional before actually trying it.
The penalties for being wrong can be rather harsh.
Here's an example: If you are flagged this year, they may not audit you this year or next year.
If you do it the third year, they can get you for all three years because they can go back three years (more for fraud, but that's a different topic).
The penalties accumulate from the date of the first offense, even if they knew and didn't tell you about it.
IANAL == I am not a lawyer
And even if I were a lawyer, I'm not your lawyer.