This is a Timezone +12 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 12,500 icons, all in the same style and quality.
The icon is describing the users time zone. It is in the shape of a wavy paper thin wall with polka dots, and has a circle with the number +12 inside of it, located on the lower right section of the wavy paper thin wall.