Abstract: A clock comprising, a case, a clockwork in the case having a plurality of pointers, a dial face in the case over which the pointers sweep about a common axis, a glass covering the dial and pointers, at least one illuminator for illuminating the dial and pointers and a ring having a face with spaced markings thereon which is mounted between the dial and glass and which can be manually rotated. The ring face is illuminated by the same illuminator which sheds light on the dial since the ring face faces the glass which receives light from the illuminator and illuminates both the dial and the ring face.