This icon is a part of a collection of Poniedziałek flat icons produced by Icons8. Icons follow the guidelines of iOS, Windows, and Android and are designed by a single designer, guaranteeing the consistent quality. Both PNG and vector are available.
A square with the Capital letter M lower case O inside of it. On top of the square is a smashed rectangle that has 2 vertical tiny rectangle coming out of the top. Similar to what a desk flip calendar would be