Reference Talk — 3940 Patek Philippe Perpetual Calendar
3040J 3rd Series, Credit: mh1717 - Instagram
The quintessential automatic perpetual calendar reference manufactured by Patek Philippe.
Patek Philippe introduced the ref. 3940 perpetual calendar in 1985, a true grand complication and their response to the quartz crisis. Interesting it was released alongside ref. 3970, a chronograph perpetual calendar, and is recognized as one of Pateks most important pieces in their modern history. The ref. 3940 production spanned 3 decades making it one of the longest production models in their history, 1985 to 2007. At its launch the ref. 3940 was exclusively available in yellow gold and was later made in rose gold, white gold, and platinum.
Most famously the ref. 3940 was worn daily by no other than Philippe Stern, father of current Patek Philippe CEO Thierry Stern.
Interestingly this incredible historic piece is still ‘relatively’ affordable compared to its modern counterparts however it has been gaining more and more attention throughout the watch community as of late 2019 early 2020… and rightly so.
Specifications
Movement - Automatic ultra-slim cal. 240-Q that dates all the way back to the 1970s powered by a 22K gold rotor heavy enough to provide enough force to power the watch.
Dial - Applied pointed baton hour markers with a dot outer minute track. 3 sub dials at 3,6 and 9 positions presenting the month/leap year indicator, date/moon-phase, and the day/24hr display.
Case - 8.5mm thick, 36mm in diameter. Quick set buttons at 6, 9 and 12.
The first 3940 stamped No.1 on the dial sold exclusively through BEYER, Credit: HODINKEE
Series Deep Dive
1st Series
PENDING UPDATE — Please find full 1st Series deep-dive here.
1985 to 1987
Calibre 240 Q, movement no. 770.001 to circa 770.700
3940J 1st Series, Credit: A Collected Man
Key Characteristics
‘Small recessed sub dials’
The 1st Series production was short and predominantly identifiable by the small recessed sub-dials at the 3 and 9 positions with the ‘Month’ and ‘Day’ indicators printed flush on the dial surface. A less noticeable tell is the grave accent above the second ‘E’ in GENÈVE printed on the dial, the sub-dials use a serif font and the Patek branding is small and short. The Sigma on the dial sits below the outer ‘dot’ track and the case hallmarks can be found on the side of the case.
1st Series is known for its yellow gold case however white gold and platinum cases have surfaced in the past (see photo). These cases were fitted with either a lightly-brushed, opaline dial or rare ‘dore’ gold dial. It is believed only 700 1st Series models were produced making them highly sought after. The very first 25 watches were exclusively sold through BEYER, 15 with a German dial and 10 with an English dial. (The coveted BEYER dials are covered later).
The case-back is originally solid however there were requests at the time for a display case-back which led to the short run of the 3941, an identical watch factory fitted with a display-back. 3941 was short lived as Patek began to offer the 3940 with both case-back options. 3941 ceased in 1990 as there was no longer a difference between the two models. There are thought to be as little as 35 examples of the 3941 in existence.
Extremely rare 1/1 French Dial 3940G 1st Series, Credit: Private Collector
Case hallmarks 1st Series 3940J, Credit: A Collected Man
Solid case-back 1st Series 3940J, Credit: A Collected Man
Early 2nd Series
1987 to circa 1989 - Dial Type 1
Calibre 240 Q, circa movement no. 770.701 to ~771.500
Early 2nd Series 3940J Credit: watchesbysjx
Key Characteristics
‘Beveled sunken sub-dials’
Early 2nd Series also enjoyed a short production run and features ‘beveled’ sunken sub-dials at the 3 and 9 positions. From the dial surface the sub-dials slope down to the leap year and 24 hr indicator. The ‘Day’ and ‘Month’ no longer sit flush on the dial surface, instead, can found on the ‘beveled’ slope. Mostly seen with the lightly brushed, opaline dial a small number of ‘dore’ gold dials were manufactured.
The Patek branding is slightly enlarged compared to the 1st series however the sub-dial font remains the same, also the Sigma position remains below the outer track. Early 2nd Series had the same case back scenario as the 1st Series and can be found with the original solid back or the requested display back. The hallmarks stamped on the side of the case.
Early 2nd Series 3940J Credit: jmerce - WatchProSite
22K stamp on the gold rotor, early 2nd Series 3940J Credit: HODINKEE
Late 2nd Series
1989 to 1995 - Dial Type 2
Calibre 240 Q, movement no. ~771.500 onwards
Late 2nd Series 3940J Credit: watchesontime - Instagram
Key Characteristics
‘Leap Year indicator cross hairs, low Sigma position & hallmark stamps’
The most distinguishable visual difference to the early 2nd Series are the cross hairs dividing the quadrants on the leap year indicator at the 3 o’clock position.
Late 2nd Series are commonly mistaken for 3rd Series due to the cross hairs however there are a number of ways to tell them apart.
Late 2nd series movement numbers are a continuation of the Early 2nd Series both using the cal. 240Q. The Sigma is printed below the outer track and the sub-dials remain a serif font type, as with the early series, note the ‘5’s’ almost closing up and the way the ‘J’ in ‘Jan’ is styled. Hallmarks appeared on the case side however towards the end of the 2nd Series the hallmarks began to appear on both the side of the case and underneath the 5 and 7 lugs.
These late 2nd series came with both case-back options except for the introduction of the Platinum model that came exclusively with a solid case-back.
Serif sub-dial font, late 2nd Series 3940G Credit: A Collected Man
5 & 7 lug hallmark stamps, late 2nd Series 3940J Credit: watchpool24
3rd Series
1995 to 2007
New calibre series 240/114, movement no. ~ early 3.120.000 onwards
Inline Sigman, 3rd Series 3940G Credit: Bazamu
Key Characteristics
‘Inline Sigma, modern sans serif font & calibre series updated to 240/114’
The 3rd Series takes a lot of its design cues from the late 2nd Series dial and at a glance the two can easily be confused however there are many differences to note.
On the 3rd Series dial the Sigma has moved up and sits ‘inline’ with the outer track. The sub-dials were also updated introducing a more modern sans serif font type, first with the 6 o’clock sub-dial, followed closely by the 3 & 9. A new calibre series was introduced, the 240/114 (see photo), and Patek switched to a new numbering system. The hallmark position moved from the case and lugs to just just the lugs around 2004, all 4 lugs are stamped. Finally the gold rotor is stamped with the Calatrava cross.
From 1997 onwards all models came with a deployment buckle. The 3rd series came with both case-back options except for the Platinum examples that came exclusively with a solid case-back.
San serif sub-dial font, 3rd Series 3940G Credit: A Collected Man
Movement stamped Cal. 240/114, Hallmark on all lugs and Calatrava cross on the rotor, 3rd Series 3940G Credit: Bazamu
Exploring Variants Across the Series
Precious Metals
3940J Yellow Gold - All Series
18K yellow gold cases are the most common, available throughout the 3 decades of production. Mostly seen with a lightly-brushed, opaline dial however there were a limited number of 1st and 2nd Series that came with the ‘Dore’ gold dial.
3940J 1st Series, Credit: TheKeystone
3940R Rose Gold - 2nd & 3rd Series
Made from 18K Rose Gold ‘Pink Gold’ case was available from Late 2nd Series onwards and featured the lightly-brushed opaline dial. Rose gold models are believed to have made up just 20% of production number from 2nd Series onwards.
3940R Late 2nd Series, Credit: European Watch Company
3940G White Gold & 3940P Platinum - *1st, 2nd & 3rd Series
*As mentioned earlier there has been a 1st Series found in a white gold case.
The significant heft of the platinum case is the most noticeable distinguisher between the the 3940G and 3940P. The platinum model also came exclusively with a solid case-back whereas the white gold featured the display back. Both models are thought to have shared the same dials and can be found with either the lightly-brushed, opaline/silvered dial depending on production range.
3940G 3rd Series, Credit: Bazamu
3940P 3rd Series, Credit: A Collected Man
Dial Language Variants
There have been a number of 3940 dial languages surface over the years. Examples have been seen in German, English, Italian, French, Spanish (not shown below). *Please reach out if you own a Spanish dial.
German Dial, Credit: A Collected Man
English Dial, Credit: A Collected Man
‘Rare’ Italian Dial, Credit: A Collected Man
‘Very rare’ French Dial, Credit: Private Collector
Moon-Phase Disc Variants
Ref. 3940 across all metals features a yellow gold moon/stars in the moon-phase indicator however later 3rd Series white gold and platinum models exhibit silver moon/stars.
3940G, yellow gold moon/stars disc, Credit: A Collected Man
3940P, silver moon/stars disc, Credit: A Collected Man
9 o’clock Sub-Dial Patina
Patina is known to appear on the lower half of the 24hr indicator at the 9 o’clock sub-dial. This patina can appear across all 3 Series and 4 references, 3940 J,R,G and P. This discoloration can range dramatically from a light brown to a deep purple. There is limited information as to why this discoloration appears however it is believed Patek treat the dial surface in such a way as to indicate a day and night phase within the sub-dial.
3040J Credit: mh1717 - Instagram
3940P Credit: A Collected Man
3049R, Credit: European Watch Company
3940G Credit: minyuho - WatchProSite
Important 3940 models to Know About
2nd Series Prototype…
‘The ‘X‘ Leap Year Divider’
Rarely seen is the coveted 2nd Series 3940 with the leap year indicator sub-dial divided by an ‘X’ instead of the regular ‘+’. There is only speculation surrounding the background of these rare pieces and it was the dial layout first seen on the wrist of Philippe Stern himself (photo below). This dial may be seen as a prototype or a transitional dial as the layout evolved from the ‘early’ and ‘late’ 2nd Series models, this is of course up to the collectors interpretation.
Rare 3940G Italian ‘X’ Leap Year Divider Dial, Credit: Mike H - WatchProSite
3940J ‘X’ Leap Year Divider Dial on the wrist of Philippe Stern, Credit: Unknown - SJJX WatchProZine
The Beyer 3940
The very first 25 pieces of the ref. 3940 perpetual calendar were sold exclusively through BEYER, Switzerland. The first 15 with a German dial and the final 10 with an English dial.
The very first 3940, Credit: HODINKEE
“Theodor "Teddy" Beyer was very close with Patek Philippe owner and CEO Philippe Stern, as the two weathered some of the worst times for the Swiss watch industry together. So, for the 225th anniversary of Beyer Chronometrie (in 1985), Patek Philippe allowed Beyer to have the first 25 pieces of the now-iconic reference 3940 perpetual calendar. These watches come with a salmon dial bearing a double signature and individual numbers in the sub-register at six o'clock.” - HODINKEE
An extract taken from the truly incredible episode of ‘Talking Watches’ featuring René Beyer, son of Theodor Beyer, that can be found on HODINKEE.
Case back of the very first 3940, Credit: HODINKEE
Salmon Dial London Edition (LE)
3940G LE Credit: watchrookie - Instagram
Produced for the brand’s 175th anniversary grand exhibition held at London’s Saatchi Gallery in 2015.
The timepiece is famously made from a ‘new old stock’ ref. 3940 white gold case fitted with a salmon dial in the ref. 5140 configuration/layout. The exact production number was not disclosed, however speculation ranges from 5 - the mid 20’s.
3940G LE, Credit: European Watch Company
The White Roman Numeral Porcelain Dial
A limited variant of the 3940 can be found with the ‘White Roman Numeral’ dial. The dial was produced in small quantities across rose gold, white gold and platinum, with platinum the rarest respectively. This dial was lacquered porcelain featuring black painted Roman numerals with the an outer minute track in five minute increments. Finally the dial is paired with either black/blued or matte grey javelin hands and was produced alongside both the 2nd and 3rd Series of the 3940.
3940R, Credit: ZXupes
3940G Credit: European Watch Company
