Idea of Calendar 29 Icon
It's a square with 2 ring-like objects at the top, to indicate that it's a calendar that you would flip to change the date each day. There is the number 29 inside the square, to signify that it is the 29th day of the month.
This page contains the Calendar 29 vector icon, as well as variations of this icon in different visual styles, and related icons. All icons are in the flat vector style, however, differ by the line thickness, fill, and corner radius.