This is a Calendar 2 icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 12,400 icons, all in the same style and quality.
There is a large square with the number 2 printed in side. On top of the rectangle butted against it is a short rectangle that is the same with as the square. From its top equally spaced is 2 vertical running tiny rectangles for the hinges.