Patek Philippe. An extremely fine 18K gold perpetual calendar chronograph wristwatch with moon phases, 24 hour and leap year indication, Certificate of Origin, additional solid-gold case back, setting pin and box

The present reference 3970 is a highly attractive example of the celebrated model.
Purchased by the present owner in 2004, the watch has remained in his collection ever since and is now being offered only for the second time at auction.

Reference 3970
In 1986, Patek Philippe launched a new generation of the perpetual calendar chronograph wristwatch, designated reference 3970, replacing the hugely successful reference 2499. The main difference in the movement was the arrival of the new Lemania base ébauche which replaced the Valjoux movement used for the previous 50 years.

Starting with movement number 875'000, the first series of reference 3970 were produced with a solid snap on back, comprising approximately 100 examples. The second series introduced a solid screw back, designated reference 3970E (E for étanche, French for waterproof). A small number of watches from both series were also available with a sapphire crystal back, designated reference 3971E.

In 1989, a third series of ref. 3970 was launched, fitted with a solid screw back as well as an additional sapphire crystal display screw back.

Reference 3970 was discontinued in 2004 and replaced by reference 5970.

While production of the reference 3970/3971 may have ended only thirteen years ago, these modern yet classic perpetual calendar chronographs have become a must-have for the discerning collector of complicated wristwatches.

Reference 3970 and calibre 27-70 Q are illustrated in: Patek Philippe Wristwatches, Martin Huber & Alan Banbery, second edition, pp. 305 – 308, reference 3971 in Patek Philippe Museum - Patek Philippe Watches, Vol. II, p. 307.