Seiko Astron watches unite time and space like seen never before, boasting a design that reflects the grandeur of this technical achievement. The Seiko Astron receives all the power it needs from light absorbed through the dial. It uses all kinds of light and there is a power reserve indicator to show the amount of energy stored. Astron receives GPS signals even when the wearer is walking or in a vehicle. If you can see the sky, you can tell the exact local time, even on the move. Seiko Astron has a Perpetual Calendar that is correct until February 28, 2100.