@Onguard2000 my apologies..... let's use a specific example.
Let's say House #1 was purchased on July 1, 2020 and you lived and owed it until Sept 11, 2023, when you closed on and moved into House #2. You still own House #1, but do not live in it.
House #1 is placed on the market. As long as House #1 is sold by Sept 11, 2026, you still would meet the test of owning it and living it in for 2 of the past 5 years. On that date, the measurement period would be from Sept 12, 2021 - Sept 11, 2026 and during that 5 year span you lived and owned it from Sept 12, 2021 - Sept 11, 2023. After Sept 11, 2026, you would no longer be able to say you lived and owned it for 2 of the last 5 years (and technically, it's 730 nights).
Now, in fact, House #1 sells on March 1, 2024. In order for you to qualify for the exclusion on House #2, you could not sell it until March 1, 2026. While you would meet the two years ownership and residency test on Sept 11, 2025, you can't use the exclusion more than once in a two year period, so you'd have to wait until March 1, 2026 to sell House #2 and get the exclusion.
