Accutron Date Code Lookup
Every vintage Bulova Accutron carries a two-character date code — a letter for the decade and a digit for the year — stamped on the caseback and movement. M means the 1960s, N means the 1970s, so M0 is 1960 and N9 is 1979. Enter yours below to date the watch instantly.
Accutron Date Code Decoder
Enter the letter-plus-digit code from your Accutron caseback or movement (e.g. M7). The decoder reads the letter as the decade and the digit as the year.
Tuning-fork Accutrons were made from 1960 to 1977, so a genuine one almost always shows an M or N code. The code dates the case and movement — see what it does and doesn't tell you.
The Bulova Accutron was the first electronic watch to keep time with a humming 360 Hz tuning fork instead of a balance wheel. Launched in 1960 and produced until 1977, it used Bulova's factory-wide dating system: a single letter for the decade followed by a single digit for the year. Unlike the single-digit codes on many Japanese watches, an Accutron code is unambiguous — M4 can only mean 1964, and N3 can only mean 1973. This guide shows exactly where to find the code, how to read it, how it maps to the tuning-fork production era, and the red flags that separate a correct, original watch from a re-cased or franken build.
How the date code is structured
An Accutron date code is exactly two characters. The first is a letter that fixes the decade; the second is a digit from 0 to 9 that gives the year within that decade. Read them together and you get a single, exact year.
Where to find the code on your Accutron
The date code is stamped in two places: the caseback and the movement. On many Accutrons the caseback stamp is on the inside, so you may need to open the case to read it. It is small — look for a lone letter-and-digit pair among the reference and serial markings.
On the caseback
Look on the inside or outside of the caseback, near the case reference (often the same number as the movement, such as 214 or 218) and the serial. The date code is the isolated two-character pair — don't confuse it with the multi-digit serial or the model reference. On snap-back cases you'll usually find it inside; on screw-backs it may be laser-etched outside.
On the movement
Bulova also stamped the date code on the tuning-fork movement itself, typically near the coils or the caliber marking. This is useful for cross-checking: if the caseback and movement codes disagree, one of the two parts has been replaced, which matters for originality and value.
The tuning-fork movement that defines a vintage Accutron
What makes an Accutron an Accutron is the 360 Hz electronic tuning fork. Two coils drive a metal fork that vibrates 360 times a second; a tiny index wheel with hundreds of teeth converts that hum into rotation. This is why a running vintage Accutron emits a faint continuous hum rather than a tick.
The main tuning-fork calibers you'll see, each carrying an M or N date code, are the 214 (1960–1977, the original, crown on the caseback), 218 (from 1966, conventional side crown with date), and the later 219, 221, 224 and 230 variants of the 1970s. The caliber number usually appears alongside the date code, which is why they're easy to cross-check.
The decade-letter chart
After 1949, Bulova rolled the alphabet forward one letter per decade. The letter O was skipped to avoid confusion with zero. For the tuning-fork Accutron, only M and N are in play — L predates it and P is the quartz era after 1977.
M — the 1960s
- M0 — 1960
- M5 — 1965
- M1 — 1961
- M6 — 1966
- M2 — 1962
- M7 — 1967
- M3 — 1963
- M8 — 1968
- M4 — 1964
- M9 — 1969
N — the 1970s
- N0 — 1970
- N5 — 1975
- N1 — 1971
- N6 — 1976
- N2 — 1972
- N7 — 1977
- N3 — 1973
- N8 — 1978*
- N4 — 1974
- N9 — 1979*
*N8/N9 exist in the Bulova system but fall after tuning-fork production ended in 1977, so they appear on quartz-era Bulovas rather than vintage Accutrons.
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Start AuthenticationWhat the code dates — and what it doesn't
The date code marks when the case (and separately, the movement) was manufactured. That's normally within a year of when the watch was sold. It is not a guarantee of authenticity: parts get swapped over 50+ years, and a service movement or replacement caseback can carry a different code from the rest of the watch.
It dates the component, not the sale. A watch coded N1 was cased in 1971 and likely sold in 1971 or 1972. That's exact enough for almost every purpose — insurance, collecting, matching to a birth year.
Caseback and movement can disagree. Because both carry a code, compare them. A one-year gap is normal; a decade gap means a service or franken movement. This is where the code becomes an authenticity tool rather than just a dating one.
It never proves the dial or hands are original. Re-dials are the most common issue on vintage Accutrons, especially the Spaceview (which shows the movement through the front). The date code can be perfectly correct on a watch with a refinished dial.
Red flags on the date code and caseback
Caseback and movement agree (1971), stamps are crisp and correctly placed. Consistent with an original watch.
A 1962 case with a 1976 movement (or vice-versa) means parts were swapped — a service replacement or a franken build.
- ✖No M or N code at all. A tuning-fork Accutron (1960–1977) should carry an M or N code. An L, or a much later code, on a watch sold as vintage tuning fork is a warning.
- ✖Caseback and movement codes far apart. A gap of more than a year or two points to a replaced part.
- ✖Impossible letter+digit. The second character must be a digit 0–9. A letter in the second position, or a code like ‘O3’, is not a valid Bulova code.
- ✖Re-dial signatures. Fuzzy printing, wrong ‘Accutron’ font, or a date-window / Spaceview cutout that doesn't match the caliber — the date code can be genuine while the dial is not.
- ✖A modern Accutron sold as vintage. Post-2020 Accutron watches are a separate brand with no tuning fork and no vintage date code.
Vintage Accutron vs the modern Accutron brand
This decoder applies only to the vintage tuning-fork Accutron, a Bulova product line made from 1960 to 1977. Those watches use the Bulova letter-plus-digit date code and hum at 360 Hz.
In 2020 the Accutron name was relaunched as a standalone brand. The flagship Spaceview 2020 uses a modern electrostatic movement, not a tuning fork, and these watches do not carry the vintage letter-plus-digit date code. If your watch is a post-2020 Accutron, this lookup won't apply — check its own reference and serial instead.
Common Accutron date code questions
What year is my Accutron with code M6?
M6 is 1966. The M fixes the decade (1960s) and the 6 is the year. The same reads M0 = 1960, M3 = 1963, N1 = 1971 and N5 = 1975.
Where exactly is the code on a 214 Spaceview?
On the caseback (often inside on snap-backs) near the reference, and again on the movement. The 214 has its crown on the back, so the case markings sit around that setting crown.
Does the code prove my Accutron is real?
No. It dates the case or movement but says nothing about the dial, hands, or whether parts belong together. Treat it as one signal among several — caliber, tuning-fork hum, dial quality and matching codes all matter.
My code starts with a letter other than M or N — what does that mean?
L is the 1950s (before the Accutron), and P is the 1980s (after tuning-fork production). On a watch presented as a vintage tuning-fork Accutron, anything outside M/N warrants a closer look at whether the part is original.
Is there a serial-number database for Accutron?
Bulova serials aren't a public year-lookup the way the date code is — the two-character date code is the reliable dating tool. Enthusiast archives (myBulova, the Accutron collector pages) are the practical references for calibers and models.
Important Note
The date code dates the case and movement — it is one signal, not proof of authenticity. Combine it with the caliber, the tuning-fork hum, dial and hand originality, and matching caseback/movement codes. For a valuable or uncertain vintage Accutron, an in-person inspection by a certified watchmaker is always the gold standard.
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