Aircraft Clock, 8-day Civil Date Indicator Aeronaval (CDIA) WWII
Here is a fine example of a WWII-era CDIA Aircraft Clock, 8 day, 24-hour-dial, made by Waltham.
According to the Waltham website:
Approximately 134.000 CDIA aircraft clocks where produced and equipped with Waltham’s famous 37 size, 8-day movement, housed in a black aluminum case secured to the aircraft’s instrument panel. The crystal glass was secured by a bezel and gaskets to seal the movement against dust. The bezel assembly enclosed the civil date quick set button, positioned at the 15 o’clock numeral. The winding and setting crown was positioned adjacent to the quick set button. The dial had a lusterless black finish with printed indexes and numbers. ...The civil date, 31-day sub-dial was located at the center of the main dial, with numerals and indexes. Large Arabic numerals indicated the even-numbered hours and, small Arabic numerals indicated the odd-numbered hours. The CDIA was mounted on board of several U.S. Navy Airplanes, such as the F6F Hellcat, as well as the bombardier B24 Liberator, in services throughout World War II.
The date is set by depressing the small button just above the winding knob with a narrow tipped tool such as a paperclip, and the date pointer advances the date for each depression. The clock runs, but we cannot guarantee its accuracy or if it lasts 8 days.