This is a Timezone -1 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 12,300 icons, all in the same style and quality.
This icon represents timezone -1. It is a ruffled folded rectangle shape with lots of dots on it. In the right hand bottom corner is a fairly large circle with -1 in the center. Both the top and bottom have jagged folded sides.