How many man hours does it take to port an Android app from 5.0 to 4.4?

Question

Android

Good afternoon, the essence of the question is that how long does it take to adapt the application to an older version of android?
I perfectly understand that all cases are individual and an accurate assessment can be made only when the application is in front of your eyes. But still, is it possible to evaluate the work from and to. And what problems can be encountered at this stage?

Answer 1

From 0 to several years.
It is impossible to evaluate without knowing the details of the project.