Free tool
Pick a brand to check what production era a serial number dates to — and where the dating information comes from.
A serial number identifies an individual watch and, for many brands and eras, roughly when it was made. It does not authenticate anything by itself: matching a documented range only shows that a number like it was issued, not that the specific watch in front of you is genuine. Each brand below has its own numbering history, its own quirks, and its own point where public dating information runs out — every page explains all three, with a source for every claim.
This tool never fabricates a range it cannot back with real, cross-referenced horological record. Where a brand's numbering is genuinely undocumented for a given era, the page says so rather than guessing.