The short answer
A real Saxonia with a date runs on an in-house Lange movement, and the date mechanism is part of that movement. Most fakes pair a generic automatic with an off-the-shelf date wheel, then drop it into a case shaped like a Saxonia. So check the movement first. If the caseback is sealed, or the seller will not let a watchmaker open it, end the conversation right there.
Movement tells
The back of a Lange is where replicas fall apart. Look for these details and compare them against photos of the real caliber.
- Hand-engraved balance cock with a floral scroll. Each one is cut at the bench, so the pattern flows and the cuts show depth. Fake engraving is stamped or laser-etched: shallow, mirrored, and identical across examples.
- Glashütte ribbing across the three-quarter plate, with edges that stay straight and spacing that stays even.
- Blued screws with polished heads and slots that catch light at an angle.
- Screwed gold chatons around the jewels on many Lange calibers. Gold, not brass, and the screws sit flush.
- Engraved plate lettering: the brand name, "Glashütte i/SA," the caliber number, and "Made in Germany." Fake engraving looks burned into the metal and slightly fuzzy at the edges.
On models with the outsize date, two separate discs share one aperture and switch as a pair in a single jump. A replica often uses a single disc or a standard date wheel, and the transition drags over several minutes.
Dial and date window
Lange printing is fine, sharp, and clean under a loupe. The ampersand in the logo has a distinct shape, the umlaut sits centered over the o, and "MADE IN GERMANY" has room to breathe under the name. Fakes print heavier type, crowd the text, or borrow a modern sans-serif for the lower line. On the outsize date, two discs sit inside a recessed frame with even margins. Reject any watch where one disc sits higher than the other, where the numerals tilt, or where the frame edges look punched rather than milled.
Applied indices and hands are another giveaway. Saxonia hands are lancet shaped and finished with bevels that throw a bright line along the edge. Replica hands look flat and dull, and the bevel often disappears under magnification.
Case, crown, and markings
The case should feel dense in the hand, since Lange builds these in gold or platinum. Check the lugs for even polishing and a crisp step where the brushed surface meets the polished one. On the back you want the reference number, the case number, and the metal hallmarks struck clean and deep. Numbers on the case should match the paperwork. A mismatched or laser-faded stamp is a red flag.
Papers, price, and gut checks
Ask for the original box, the warranty card or booklet, and any service records. Then run the price. If a Saxonia with a date is listed at a small fraction of market value, the listing has already answered your question. For anything high end, pay for an inspection by an authorized dealer or an independent watchmaker who handles Lange. Ten minutes on a bench beats a year of doubt.