STR bookings in Dec 2023, Vrbo Payment in Jan 2024, which tax year is this?

[Kimberly C.]

Quick background, last year was my first year of real estate investing and long story short I pulled the trigger on 2 STR properties at the end of the year. Now I'm slowing getting all my tax docs ready for my CPA but I'm confused on how bookings in Dec 2023 affect my 2023 taxes.

So for the bookings that happened at the end of last year Dec 2023 but didn't get paid out until Jan 2024, do I include these bookings/income for the 2023 tax year?  Or will this be for next year when I do my 2024 taxes?