So I have a complete dataset and within this data, I have two columns of the data which are temporal - and formatted in this manner 'YYYY-MM-DD'. So what I want to do is create a scale between these two points and another scale, a little bit like below (num is a value set elsewhere).

   var scale =  d3.scaleTime()
                  .domain([d.start, d.end])
                  .range([0, num]);

What would be the right code to do this? Both 'd.start' and 'd.end' have multiple instances and I would perhaps want to loop this for each line? This is so it can be used to provide a value for drawing lines representing the data.