Combined time differences on a timeline

Hello,

I would like to summarize the follwing set of data:

I would like to do it this way:

In other words, I would like to find difference between all start and finish dates in days. Then, I woud like to combine all the differences by a common colour and display these values on a timeline.

Say, all the values are of green colour, so we have to some them up. There is a clash between the first and second differences, therefore, 01/01/2023 has 2. And accordingly, all other values have 1.