What day of the week was August 17, 1186?

The day of the week August 17th, 1186 fell on was a Sunday.

Georgenberg Pact: Duke Ottokar IV of Styria and Duke Leopold V of Austria sign a heritage agreement in which Ottokar gives his duchy to Leopold and to his son Frederick under the stipulation that Austria and Styria would henceforth remain undivided.