Lighting on a watch dial that allows the wearer to read the time in the dark. Check out Seiko's Lumi-brite technology. A feature that shows the date, and often the day of the week. There are several types of calendar watches. Most calendar watches show the information digitally through an aperture on the watch face.
Some chronograph watches shoe the information on sub-dials on the watch face.
Materials range from inexpensive cast metal through moulded plastic to solid chunks of steel or gold from which the case is machined. In Great Britain, gold cases are usually 18k, but less expensive watches are 9k. In most other countries, 14k is preferred. Caratage indicates the gold content of metal, stated as the number of parts of gold in every 24 parts, i.e. 18k gold is 18 parts of gold alloyed with six parts of metal. Platinum is becoming increasingly popular, as is titanium for its lightness.