My wife uses a spreadsheet and connected it to her calendar. Seems pretty accurate.

It is a modified version of this:

http://www.alizaaufrichtig.com/period-tracker

UK too: https://data.gov.uk/

If you wanted to get rid of windows in general, Darktable seems to be a good alternative to lightroom, for raw editing. There’s a learning curve, but there are plenty of tutorials available.

Not sure about Fusion 360 though… Maybe FreeCAD?