A fairly complex shape of three parts - an arc with ridges on left representing the sun, a slightly slanted dividing line, and a smooth arc on the right representing the moon.
This was created for GE microwaves that have an AM/PM button. So far I have labeled four GE microwaves with this button. Hopefully there are other uses because it required significant design time to make this complex yet effective shape.
The sun is on the left for AM and the moon on the right for PM.
I think it would be confusing without the dividing line.
There is a balance between the length of the dividing line and the size of the sun and moon.
Visually there is a sharp nook where the moon meets the dividing line. That is a no-no because it could be difficult to clean. Considerations -
The moon and sun should be the same size and the sun's ridges must be noticeable. To keep the sun's ridges noticeable it can't be too small. Therefore the sun and moon are generally the same size with those sharp nooks between the moon and the dividing line.
The equipment to make the tactile icons is not as exact at the image so the sharp nook is probably minimized.