Date business started using home office

Hi,

 

I owned my home with someone for 20+ years. I started using a home office in 2020. I bought the home in my own name in 4/22. I am filing with regular home office deduction.

 

What do I put as the date that I started using my home office? Technically it was 2020, but ownership changed.

 

Does the start date impact taxes when I sell?

 

Thank you!