Bulova watches from the vintage era often feature a distinctive date code system that is particularly useful for collectors. Many Bulova watches from roughly the 1920s through the 1970s include a date code stamped on the case back or inside the case back that can be decoded to determine the year of manufacture. This date code is commonly a single letter or letter-number combination that corresponds to a specific year in Bulova's production history.
The Bulova date code system is one of the better-documented vintage watch dating systems, with comprehensive tables available through collector organizations such as myBulova.com. The code is typically found on the inside of the case back (requiring removal to see) or stamped on the outside near other case markings. In addition to the date code, vintage Bulova watches may carry a movement serial number and a case serial number, which are separate identifiers.
Modern Bulova watches, produced under the Citizen corporate umbrella, use different identification systems. The case back typically displays a model number and may include a movement caliber number. These can be looked up through Bulova's product database or collector resources. The transition from the vintage date code system to modern reference numbers roughly coincides with the changes in Bulova's corporate ownership and manufacturing practices during the latter decades of the 20th century.