[Feature Request]: Plot Diurnal Cycles as Polar Charts

Polar charts look like clocks and are periodic. Maybe they are more intuitive than the line-plot currently in use?

https://matplotlib.org/stable/gallery/pie_and_polar_charts/polar_demo.html#sphx-glr-gallery-pie-and-polar-charts-polar-demo-py

I am not sure how legible they are with many lines, and if they work for all metrics. 

Maybe it is worth a try?