sub s form and schedule k how to fill out when ownership change 12/31/19, the dates are giving me a problme

I put the 12/31/19 as date sold but the breakdown on the percentage form is not working.  Do I put 1/1/2019-12/31/19 and then 1/1/2020 - 12/31/2020. Two of the shareholders are going to 0 as of 12/31/19,