Short answer
A genuine A. Lange & Sohne Saxonia date display uses two separate number discs, one for each digit, and both digits snap to the next date at the same instant. Most fakes use a single printed disc, a slow rolling change, or two digits that never line up. If the date drags across midnight or the numbers sit at different heights, the watch is not real.
Know which Saxonia you are checking
The Saxonia Thin and the Saxonia Automatic have no date at all, so any date window on those references is an immediate sign of a fake. The Saxonia Outsize Date carries two large digits at 12 o'clock. The Saxonia Moon Phase carries a compact date at 3 o'clock beside the moon aperture. The Saxonia Annual Calendar adds an outsize date at 12 with month, day, and weekday subdials. Confirm the reference before you judge the date, because the correct layout depends on the model.
Step-by-step check
- Set the hands to 11:55 p.m. and watch the window for a full minute. A real outsize date flips in one motion. A fake moves one digit, then the other, over several minutes.
- Look at the bar between the two digits. Genuine examples show a narrow, even divider with clean edges. Copies show a thick or wavy bar, or no divider at all.
- Compare the digit shapes. Lange numerals are wide and geometric, with flat tops, thick strokes, and even spacing. Fakes use thin digits, tight spacing, or a serif font.
- Check the baseline. Both digits share one line and sit centered in the window. A fake often shows one digit raised or pushed to the side.
- Check the depth. On a real watch the discs sit behind the dial, so the numbers catch light with a soft shadow. Printed numbers look flat from every angle.
- Test the corrector for the date. Lange date models use a recessed pusher, and one press moves the date by exactly one day with a crisp click. If the date only moves through crown positions, treat it as a fake.
- Turn the watch over. Real movements show Glashutte ribbing, blued screws, and an engraved balance cock. Copies show plain plates and shallow engraving.
- Compare the caseback numbers. Reference, case number, and hallmarks should be sharp and consistent with the model you are buying.
- Weigh the watch in your hand. A gold Saxonia case feels dense for its size. Plated brass and steel copies feel light and cold.
Common tells on fakes
- A date that rolls instead of jumping
- Mismatched digit heights or widths
- Numbers printed under a flat crystal
- An aperture that is too wide, too narrow, or off center
- A date on a reference that never had one
- Soft engraving and dull polishing on the caseback
Before you pay
Ask for a video of the midnight change with a timer in frame. Ask for angled close-ups of the date window, because parallax reveals printed numbers. If the seller refuses either request, walk away.