Tax loss selling confusion?

So I am reading tomorrow Wednesday is the last day for tax loss selling.

I “thought” the last day was technically Friday so am confused what I should be doing tomorrow.

I have already lost a lot this year and have thousands in capital gain losses, so if I am selling stocks at a PROFIT this year, do I ALSO need to do this by tomorrow?

Like if I sell a stock at a profit on Thursday, does it go into the tax for 2024 OR is this just in terms of things you are selling at a LOSS?

Thank you