This Strefa czasowa -1 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 4,300 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.