Identification · dating tool

How old is my watch or clock?

Tick the features you can see. Each one was invented, required by law or in fashion at a known time; the Atlas works out the range they all allow, the most likely period, and warns you when they cannot all be original.

How to date a watch or clock in five steps

Look for documents first. A maker's archive extract, a dated receipt or a presentation inscription beats every other clue. Large makers (Waltham, Elgin, Hamilton, Longines, Omega, Rolex and others) also have published tables that turn a movement's serial number into an approximate year.
Read the marks in the case. A British hallmark includes a date letter that gives the year the case was assayed. Swiss, French and other control marks do not give a year, but each was used only for a known period. Country names such as 'West Germany' or 'USSR' also set firm limits.
Identify the technology. How the piece is wound and set, which escapement it has, whether it has a balance spring, a rotor, shock protection, a battery or a quartz crystal: each was invented at a known date and was usual for a known period.
Check the style. Dial, hands, case shape and lume follow fashions. Style is the weakest evidence on its own, because good copies and later revivals exist, but it helps to choose within a range.
Compare like with like. Look at dated pieces of the same kind in the catalogue: the same maker, the same type and the same features. If yours matches pieces of one period closely, that is good supporting evidence.

Which evidence counts most

Not all clues are equal. Documents and serial numbers date a particular piece; inventions and laws set limits; style only suggests. When clues disagree, trust the stronger kind, and ask whether a part has been changed.

Evidence	What it dates	Strength
Archive extract, dated receipt or inscription	Documents this piece	Strong, if the paperwork belongs to it
Movement serial number in a maker's table	The movement's year (approximate)	Strong for the movement; the case may differ
British hallmark date letter	The year the case was assayed	Strong for the case
Legal marks and country names	A firm window (e.g. 15 ct 1854–1932, 'West Germany' 1949–1990)	Strong limits, wide window
Inventions (balance spring, rotor, Incabloc, quartz)	Not earlier than the invention	Strong lower limit
Style of dial, hands and case	When a fashion was usual	Weak alone; useful with others

Remember: parts can be younger than the whole

A hallmark dates the case, a serial number the movement, and a dial can be repainted at any time. Old watches were recased and old clocks given new dials or escapements. Where two parts give different dates, the piece may be a later assembly — still interesting, but described honestly as such.

Questions people ask

How do I find out how old my watch is?

Start with any documents, then read the marks in the case and identify the movement's technology. A movement serial number checked against the maker's published table usually gives the year to within a year or two; without one, combine several features — the overlap of their date ranges is a fair estimate. The tool on this page does that overlap for you.

Can a serial number tell me the year?

For many large makers, yes: published production tables turn movement numbers into approximate years. They date the movement, not the case, and they are approximate because numbers were allotted in blocks. Case numbers belong to the case maker's own series.

How do I date a British hallmark?

Find the assay-office mark (a leopard's head for London, an anchor for Birmingham and so on), the standard mark and the date letter in its shield. The letter, its typeface and the shape of the shield together give the year from the assay office's published tables. It dates the case, not the movement.

How old is my grandfather clock?

For an English longcase clock, the dial is the quickest guide: brass dials with cast corner ornaments are usual before about 1770–90, white painted dials after the early 1770s; an arched top is later than about 1700–20; a single hand usually means a 30-hour clock of the 18th century or earlier. The maker's name on the dial can then be checked in published directories of clockmakers.

Why does the tool say my features cannot all be original?

Because their date windows do not overlap — for example a 15 carat British gold mark (used until 1932) with an Incabloc balance (from 1934). Either one feature has been misread, or the piece has been altered: a recased movement, a replaced dial or hands, a converted escapement. Untick each clue in turn to see what the others say.

Does an older piece mean a more valuable one?

Not necessarily. Maker, quality, condition, originality and demand matter more than age alone; many 19th-century watches are worth less than a sought-after 1960s sports watch.