Bulova watches have serial numbers located on the bottom of the outer case located on the back of the watch. In older models of Bulova watches, three Roman numerals can be found on the rim of the movement case that match the last three digits of the serial number.
The serial number of a Bulova watch is used to determine the date when the watch was manufactured in watches that were manufactured after 1926. The first digit of the case serial number from 1926 until 1950 indicated the year in each decade that the watch was manufactured. There are a number of serial number exceptions that have taken place over the years of Bulova watch production.