I know there are various online webpages that calculate optimum Solar Panel Tilt Angles, however I decided to make my own excel spreadsheet to get the numbers as close to how I wanted them to be - for example the spreadsheet provides the angles right down to the daily level; so if I'm going to the bother of adjusting my panels I can set them to exactly how I want them.
If your interested, I've posted it as a free open source project on Github here: https://github.com/roblatour/SolarPanelTiltAngleCalculator
