Time and maths

I'm trying to keep track of the time spent on quilting this quilt - I'm hopeless at stopping and starting the clock, but I can work out the average quilting time for each 'unit', multiply, an add them up. Currently, I've spent 2.5h quilting the centres of each block (below) and 3h marking and quilting the structural lines in the border.

I've also worked out that marking and quilting each of themain units (below) takes an average of 65 minutes. Although there are only 6 complete units, when the half and quarter units are added, there are 12, giving a total of 13h for these.

That's 18.5 h so far. I'm now starting the curved cross-hatching in the gaps in the blocks (below).

I'm marking these freehand before quilting them - that seems to work best. I need to do a few (I've only done the four on the first block so far) then I'll time some (the clock on the machine is ideal for this) to work out an average time for them. Then there are the borders to fill - I'm still dithering over the patterns..