Waltham CDIA (Civil Date Indicator, Aeronautical) 

If you have a Waltham CDIA clock you need serviced, you will find  services and charges listed on the Aircraft Clock Restorations and Repair Services page.

The Waltham CDIA was used extensively in WWII USN and Marine Corps aircraft.  Its large 2 3/4 inch dial and continuously running sweep seconds hand was easy to read and the dual mainsprings assured reliability.  This is the clock found in the Corsairs and other late Pacific theater aircraft.

The movement used in this clock was extremely rugged and versatile.  Variations of the basic movement were used in everything from automobiles to armored vehicles and aircaft.  The USN kept these in service until the 1980s although I do not know for what applications.

The Civil Date changes at midnight.  The corrector button short months is just above the winding knob and is actuated by a simple push with a pencil point.  The movement is 8 days running and is wound normally.  The time is set by pulling the winding knob away from the case. To increase ruggedness under field conditions, Waltham chose to forgo the mechanism that holds the knob in the setting position.  A spring applies force to return the knob to the winding position the whole time the hands are being adjusted.  This also prevented the clock from being left in the hand setting mode which could adversely affect the timekeeping.

Like the Elgin and Hamilton 37500 and the USN Jaeger A-10, the CDIA has a 24 hour dial.

Cost of Fully Refurbished CDIA Clock with  unbreakable mainsprings, Certificate of Performance and 1 year warranty:  $575 plus shipping.