Large, garden variety sundial, printed in Stainless Steel PLA.

Finished models available on Etsy: https://www.etsy.com/FullSizeRender/listing/1248246196/

To use, align it towards true north and hope for clear skies (for instructions on finding true north, see: http://www.princeton.edu/~oa/manual/mapcompass2.shtml).

Inspired by/remixed from this great Instructables project:
http://www.instructables.com/id/Sundial-Watch-3D-Printing/step6/The-Classic/

More info on sundials: https://en.wikipedia.org/wiki/Sundial