This Timezone -12 icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 5,500 icons, all in the same style and quality.
A timezone -12 icon is represented with a foldout map icon and on the edge of the map there is a circle with a -12 written inside. The map will have straight lines on both sides, but on the top and bottom there will be a zig zag pattern to show it's foldout component.