Determining the age of a grandfather clock requires that you become familiar with traditional clock case materials and the country of origin of your particular clock. Grandfather clocks can be from the early 18th century to the 21st century. You can determine the date of some clocks within a year of their manufacture from the serial number on the dial by their maker; clocks from unrecognized makers will need to be dated by an expert.
Identifying Your Clock
The oldest clocks, which date back to roughly 1720, are primarily British and usually have cases made of maple or oak. A clock with a mahogany case can usually be dated to the mid-18th century, as this wood was not imported into the United Kingdom before then.
To determine the age of your clock, first verify that you have a grandfather clock, as opposed to a wall-mounted clock. Grandfather clocks, or long case clocks, are defined as clocks that stand independently on the ground and are tall enough that they do not need to be placed on a table or other furniture.
The clocks tend to be classified by how often they must be wound. The 18th century clocks are usually either eight-day clocks or 30-hour clocks, meaning you must wind them within that period in order to present the correct time, although this custom did persist into the early 19th century. The oldest clocks, dating anywhere from 1720 to 1830, usually have "1111" as a representative for the numeral "4" on the clock face, instead of the traditional roman numeral "IV." The theory is that this was purposefully done to balance out the opposing "VIII" for "8" on the other side of the clock face.
National Origin and Unidentified Makers
To identify the country from which your clock originated, note how the clock face is framed. Different countries, such as England, Germany, Scotland, and the United States, produced grandfather clocks. English and Scottish grandfather clocks are defined primarily by the ornamental fluted top, which has two distinct columns, like horns. German grandfather clocks have a more rounded top, without excessive ornamentation. Clocks produced in the United States are usually from the 20th century and show Arabic numerals on the clockface.
The country of origin also determines the time period for the most popular grandfather clocks. Germany, for example, did not begin to produce grandfather clocks en masse until around the 1880s, when Gustav Becker shifted his production from wall clocks to floor clocks. Becker stamped his seal and serial number into each of his clocks. You can find this serial number on the reverse side of the dial. If your grandfather clock bears a stamp and serial number from the German company Embee, your clock is from the 20th century and can be dated very specifically within a five-year period. Most antique clock sellers will be able to help you identify the specific year of the Embee or the Gustav Becker by researching the serial number in catalogues.
If your clock was not manufactured by a recognized maker, consult an antiques dealer to determine the type of the wood, the style of the clockface and any other period details that may help him identify the specific decade in which the clock was manufactured. Because unidentified grandfather clocks can be highly individual in their make and features, expertise is often needed to determine their age.