Our customers regularly ask how the age of an Atmos watch can be determined. For this reason, the aim of this paper is to provide a guide for further analysis.
First, the watch’s unique serial or reference number is required. This sequence of numbers constitutes the unit in question.
It can be noted that the number has a direct correlation with the age of the watch. A lower number indicates a younger watch. It is essential to read the correct numbers, as they are always arranged linearly and without any additional characters.
The serial numbers are typically located either on top of the regulator block (when viewed from above) or on the front of the watch directly beneath the hands. On some watch models, the serial number is only accessible to experts. The models in question include non-skeletonized watches, such as the acrylic glass models or the wooden model by Gruen.
The following section presents reference numbers for various watches, along with a table for determining the respective model and age. The table can be used as a rough guide for dating Atmos watches. The table provides an approximate age down to the corresponding decade but does not constitute an official table issued by Jaeger-LeCoultre. Please take these notes into consideration.
| time period | serial number |
| Reuter models 1928 – 1939 Earty JLC | 0001 – 6000 |
| 1940s | 6000 – 24.999 |
| 1950s | 25.000 – 126.999 |
| 1960s | 127.000 – 299.000 |
| 1970s | 300.000 – 519.999 |
| 1980s | 520.000 – 649.999 |
| 1990s | 650.000 – 704.999 |
| 2000 – present | 705.000 + |
