Reference:6510

Day-Date › 6510

Rolex Day-Date 6510, 1956, 18k yellow gold, smooth/domed bezel and Jubilee-era textured bracelet. Case No. 214'033. Phillips, Hong Kong Watch Auction: TWO, Lot 293.

The 6510 is the first Day-Date reference, and is widely credited with being the first wristwatch to display the day of the week in full beside the date. Marc Huguenin's 1950 and 1955 Swiss patent filings describe the mechanism, and Rolex presented the Day-Date at the Basel Fair in 1956. Early 6510 and 6511 examples are documented on Jubilee bracelets. Rolex dates the President bracelet’s creation and unveiling to the 1956 launch; Phillips also catalogs a 1955-dated 6511 with a President bracelet and clasp stamped 2.57. The clasp date belongs to that component, and the auction entry does not establish original delivery. The 6611 is strongly associated with early President fitment, but the surviving record does not prove it was first. The Day-Date was already being called “President” in some material by the late 1950s; the Lyndon B. Johnson campaign helped make that name familiar, rather than creating it from nothing.

Core facts

detail	value
reference	6510
family	Day-Date
Swiss patents	CH 322341A (instant-change date mechanism) + CH 323982A (Day-Date module), both filed by Marc Huguenin in 1955; 1950 priority filing covers the architectural ancestor
catalogue debut	Basel Fair 1956
production	c.1956–1957; 6510/6511 are generally treated as the one-year first generation
movement	caliber 1055 first-generation (7.0mm height, no Microstella, gradual midnight changeover, dial reads "Superlative Chronometer by Official Test" or "Officially Certified Chronometer")
case	36mm 18k gold Oyster; yellow, pink, and white-gold examples are documented, while platinum 6510 remains unverified
crystal	acrylic
bezel	smooth / domed (the 6511 carries the fluted bezel)
bracelet	Jubilee bracelets are documented on surviving examples; original delivery is not settled for every watch
earliest documented serial	134,636 (Italy 1956, dauphine hands, pointed baton markers, red date wheel)
predecessor	none; 6511 is the parallel fluted-bezel reference
successor	6611 (1957–1959, with cal. 1055B, President bracelet, and SCOC dial)

Where it sits in the line

The 6510 opens the Day-Date line at Basel 1956. The watch displays the day of the week in full at twelve and the date at three. Huguenin's 1950 precursor and 1955 Swiss filings document the mechanism: CH 322341A covers the instant-change date system, while CH 323982A describes the day-date calendar arrangement. The later Day-Date family retains the same basic calendar concept, but these patents do not by themselves prove that every later caliber uses identical parts.

The originals-era cluster (6510 / 6511 / 6611 / 6612 / 6613 / 6611B / 6612B) runs from 1956 through 1959 before the 1803 era replaces it. Within the cluster, the 6510 is the smooth-bezel original; the 6511 launches alongside with the fluted bezel that becomes the Day-Date signature; the 6611 follows with the upgraded cal 1055B; Rolex dates the President bracelet to the 1956 Day-Date launch, and auction listings document President fitment on a 6511 by 1957; the 6612 is the smooth-bezel sibling of the 6611; the 6613 carries a factory gem-set bezel; the 6611B and 6612B are late-1958/1959 movement-plate-revision variants with a bridge plate approximately 0.1mm thicker than the standard 6611/6612.

Published accounts commonly show early 6510 and 6511 watches on Jubilee bracelets. Rolex says the President bracelet was created for the Day-Date and unveiled at the 1956 launch. Phillips catalogues a 1955-dated 6511 with a President bracelet and a clasp stamped 2.57; the stamp dates the bracelet, not the watch head. The surviving records do not establish the bracelet fitted to every 6510 or 6511 at delivery. The 6611 is strongly associated with the President bracelet and the upgraded cal. 1055B.

Production outline

Patent portfolio (1950-1955)

A 1950 Swiss patent filing credited to Marc Huguenin describes a precursor to the Day-Date mechanism. Two 1955 filings split the calendar work: CH 322341A covers the instant-change date system, while CH 323982A describes the day-date module with its star and calendar wheels.

The filings are part of the technical background to the Day-Date. Later Rolex movements retain the same broad calendar functions, but the patent drawings are not a parts list for every 1055-series or modern movement.

Basel Fair launch (1956)

Rolex presented the 6510 and the parallel-launch 6511 at the Basel Fair in 1956. Both references used the first-generation cal. 1055: 25 jewels, 18,000 vph / 2.5 Hz, about 28.5mm in diameter, and about 7.0mm high. Documented dials carry either “Superlative Chronometer by Official Test” or “Officially Certified Chronometer”; both predate the SCOC wording introduced with the 6611. Day-disc languages vary by market and example; the later 26-language advertising figure should not be projected back onto the 1956 launch without a period catalogue.

The earliest documented case serial in the cited auction and collector material is 134,636, associated with a 1956 Italian delivery. Its dauphine hands, pointed baton markers, and red date wheel are observations from that example, not a complete rule for every early 6510. No published serial table establishes a lower production boundary.

Bezel split (1956)

The 6510 and 6511 launch in parallel as a bezel-finish pair. The 6510 carries a smooth or domed bezel in polished gold; specialist literature distinguishes "domed" from "smooth" by the degree of crown radius on the bezel face, with production-period 6510 bezels reading smooth-and-polished, sometimes with a subtle dome that catches reflected light. The 6511 carries the fluted bezel, the radial-flute pattern that becomes the Day-Date signature for the next seventy years.

The President bracelet in early Day-Date records

6611 with the original 1957 President bracelet, three-link semi-circular construction. An early example of the bracelet Rolex designed specifically for the Day-Date.

Rolex dates the President bracelet’s creation for the Day-Date and its unveiling to the model’s 1956 launch. The 6611 is closely associated with early President production, but Phillips also catalogues a 1955-dated 6511 with a President bracelet and clasp stamped 2.57. The auction record does not establish factory delivery for that watch or for every 6511. Early bracelet links and clasps vary; use the bracelet guide and date each bracelet as a separate component.

Caliber upgrade (1957, cal 1055B)

The 6611 also introduces the upgraded cal 1055B: 7.1mm height (0.1mm taller than the original cal 1055), free-sprung Microstella balance (the four-screw gold-mass adjustment on the balance rim that defines Rolex regulation through to the modern cal 3255), Breguet overcoil hairspring (Antiquorum's October 2002 Lot 37 essay confirms the construction), and COSC chronometer certification. The 6611's dial introduces the "Superlative Chronometer Officially Certified" four-line text block at six o'clock. The cited Day-Date records place the SCOC line with the 6611; they do not establish a first across every Rolex line. Earlier 6510 / 6511 examples retain the pre-COSC "Superlative Chronometer by Official Test" or "Officially Certified Chronometer" lines.

A small number of transitional 6510 examples surface with the upgraded cal 1055B and the SCOC dial line. Phillips and Antiquorum essay tradition treats these as transitional builds where the reference case was already stamped 6510 but the movement and dial received the upgraded specification. The published auction record documents only a small number of these transitional examples.

Originals-era closeout (1958-1959)

The 6611B and 6612B sub-variants surface in late 1958 and 1959 production. Italian Watch Spotter documents the distinction: "A very limited number of specimens of 6611 have a different bridge plate, 0.1mm thicker. These specimens can be recognized thanks to the specific reference 6611B and, for their extreme rarity, are highly sought after by collectors." The "B" suffix is a Rolex-internal mark for the bridge-plate variation. The external case stamping reads "6611", with "6611B" appearing in service paperwork and on the inner caseback. The 6612B carries the same bridge-plate variation on the smooth-bezel platform.

Production of the entire originals-era cluster ends in 1959 when the 1803 / 1804 / 1806 / 1807 / 1811 cluster, the 4-digit Day-Date era anchored by the 1803, takes over.

Movement notes

Caliber 1055 first generation (6510, 6511)

• 25 jewels
• 18,000 vph / 2.5 Hz
• 28.50mm diameter, 7.0mm height
• Self-winding bidirectional rotor with red-anodised reversing wheels
• Swiss lever escapement, Kif anti-shock
• Approximately 42-hour power reserve
• Day-and-date complications via Huguenin's CH 322341A + CH 323982A architecture
• Gradual rather than instantaneous calendar changeover is reported for early 1055 examples; the exact timing varies by movement condition and is not a reliable dating test.
• No quick-set calendar. The day and date are advanced by running the hands through midnight.
• No quickset. Date and day advance only by running hands through midnight.
• No Microstella balance, no COSC certification, no SCOC dial line.

Caliber 1055B second generation (6611, 6612, 6613, 6611B, 6612B)

• 25 jewels
• 18,000 vph / 2.5 Hz
• 28.50mm diameter, 7.1mm height (0.1mm taller than first-generation cal 1055)
• Self-winding bidirectional rotor with red-anodised reversing wheels
• Free-sprung Microstella balance: the four-screw gold-mass adjustment on the balance rim, first deployment on a Day-Date and the regulation system that defines modern Rolex through the cal 3255
• Breguet overcoil hairspring (Antiquorum October 2002 Lot 37 essay confirmation)
• COSC chronometer certified, first Day-Date generation and first Rolex reference of any line to carry it
• Dial designation "Superlative Chronometer Officially Certified" first appears on the 6611 dial
• The 1055B addresses the early movement's calendar-changeover problem, but the cited auction and editorial sources do not establish a universal changeover time for every surviving example.
• 6611B / 6612B variants carry a bridge plate approximately 0.1mm thicker than the standard cal 1055B; otherwise identical.

The cal 1055 / 1055B architecture is the founding day-date complication caliber and the architectural ancestor of every subsequent Rolex day-date movement. The lineage runs through cal 1555 (1959-c.1965, 1803 early), cal 1556 (c.1965-1977/78, 1803 late, hacking added 1972 mid-production), cal 3055 (1977-1988, 18038 era, single quickset, 28,800 vph), cal 3155 (1988-2019, 18238 / 118238 era, double quickset), cal 3156 (2008-2015, 218238 Day-Date II, 3155 scaled up), and cal 3255 from 2019.

Dial map

Production-volume dials

Silver, champagne, and black stick or baton indices on the 18k yellow gold case. Pink-gold and white-gold cases pair with appropriately-toned dials. The dial text reads "Rolex Oyster Perpetual" at the top, day-of-week in the cut-out at twelve in the full-word format Huguenin's patent introduced, the date window at three, and one of three chronometer designation lines near the bottom edge:

• "Superlative Chronometer by Official Test", pre-SCOC, appears on early 6510 / 6511 examples
• "Officially Certified Chronometer", pre-SCOC alternative, appears on 6510 / 6511 examples
• "Superlative Chronometer Officially Certified", SCOC dial designation, first appears on the 6611 in 1957 and becomes the Rolex standard from that point forward

The chronometer-designation line is the single cleanest dial-side dating anchor for the originals-era cluster. The first two formats sit on 6510 / 6511 (cal 1055 first-generation); the third (SCOC) is the 6611 introduction.

Earliest 6510 dial configuration (case 134,636)

The earliest documented example carries pointed baton markers (replaced by rectangular indices on later production), dauphine hands (replaced by alpha hands on later production), and a red date wheel (replaced by black-on-white discs through standard production). Lume is radium; the 1962 tritium transition arrives on the 1803 generation, and no originals-era dial carries factory tritium.

Black gloss dials

Surface on 6611 and 6612 examples with applied gold indices. Less common on 6510 production. The black lacquer dial of the period uses radium-painted plots at the hour positions; oxidation produces honey or chocolate tropical patterns on some surviving examples, with genuine factory-tropical distinguished from sun-faded original via same-batch documentation.

Diamond-set indices

Documented on platinum 6612 / 6613 examples. The Phillips Glamorous Day-Date Lot 43 (8 May 2015) platinum-diamond 6612 carries 8 round-cut and 2 baguette-cut diamond hour markers, with the baguettes at six and nine o'clock. This is the headline cluster lot; see Auction record.

Day-disc language variants

The 1956 launch catalogue offered English, French, Italian, Spanish, and German, the five major European retail markets at launch. Dutch and Swedish surface on 6611 / 6612 production as mid-1950s additions. Arabic day discs surface on 6611 / 6612 production from approximately 1958, after the 6510 / 6511 cluster's run; the 6612B "Lone Star" in platinum is the canonical Arabic-script originals-era piece, with platinum case, platinum President bracelet, and Arabic day-and-date inscriptions. The Arabic platinum configuration was acceptable in Islamic culture because the platinum case avoided the gold-on-men prohibition. Japanese, Chinese, Russian, Hebrew, and Greek discs are later additions, none documented on originals-era cataloged production.

Roman-alphabet day discs are the rule on the 6510 / 6511. Day-wheel swapping is endemic in the vintage market, and same-batch documentation distinguishes factory-original day discs from later-period service swaps; the language on a surviving 6510 should match the period catalogue retail market.

Case, bezel, crystal, and crown notes

36mm three-piece Oyster construction (case, screw-down crown, screw-down caseback). The 36mm Oyster envelope becomes the Day-Date standard for the next fifty-two years; the 1803, 18038, and 118238 all share the dimension. The 218238 Day-Date II breaks it in 2008 for the 41mm case.

Case materials

The 6510 is documented in yellow, pink, and white gold. Period catalogues and auction descriptions use “pink gold” and “rose gold” interchangeably; the alloy should be identified from the case marks or source description rather than from colour alone.

Platinum 6510 is not documented in the sources used here. Rolex Magazine describes the first launch examples as pink or yellow gold on Jubilee, while later auction material documents white-gold Day-Dates. The earliest platinum examples in this reference sequence are generally catalogued as 6612 or related 66xx references; a platinum 6510 should therefore be treated as an attribution requiring lot-level proof.

Caseback

Screw-down. Inside the caseback, Rolex stamped the reference number "6510" plus quarter-year Roman-numeral lot codes that date the caseback's manufacturing run. Outer casebacks are plain gold on civilian production; presentation engravings are owner-added.

Bezel

Smooth or domed on the 6510, in polished 18k gold matching the case material. The fluted bezel that defines the modern Day-Date silhouette is the 6511's signature in the parallel-launch pair. Specialist literature distinguishes "domed" from "smooth" by the degree of crown radius on the bezel face; production-period 6510 bezels read smooth-and-polished, sometimes with a subtle dome that catches reflected light.

Crown

Twinlock screw-down, the standard sport-line crown architecture the 6510 shares with the Submariner, GMT-Master, and Datejust siblings of the period.

Crystal

Acrylic. Sapphire-crystal Day-Dates do not arrive until the 18038 in 1977.

Bracelet

Early 6510 examples are documented on five-link Jubilee bracelets, made for Rolex by Gay Frères and related suppliers. The Jubilee had already been used on the 1945 Datejust, so its appearance on the first Day-Date fits the period's bracelet allocation.

Rolex dates the President bracelet to the Day-Date’s 1956 launch. The auction record documents both Jubilee and President bracelets on early Day-Dates, including Phillips’s 1955-dated 6511 with a 2.57 President clasp. That evidence does not prove which bracelet accompanied every 6510 when new. Compare the bracelet and clasp on the individual watch; their dates do not date the head.

Published 6510 examples include Jubilee bracelets, and other surviving heads may carry later replacements or period changes. Do not infer original delivery from the reference or from the bracelet style alone. A clasp code dates the bracelet component, not the case.

Auction record

The originals-era cluster's two headline lots sit on different sub-references but both inform the 6510 collector market.

Phillips Glamorous Day-Date, Geneva, 8 May 2015, Lot 43

Platinum diamond-set 6612, c.1958. One of two known platinum 6612s with consecutive case numbers; the sibling is documented in John Goldberger's 100 Superlative Rolex Watches (Damiani Editore, 2008, ISBN 9788862080194). Dial carries 8 round-cut and 2 baguette-cut diamond hour markers, with the baguettes at six and nine o'clock. Estimate CHF 100,000-200,000; hammer CHF 473,000. The result is recorded here as a lot-level comparison for the early Day-Date references.

Phillips Glamorous Day-Date, Geneva, 8 May 2015 (separate lot)

6511 in 18k yellow gold, c.1955, complete with guarantee, wallet, and box, case No. 111,654. Estimate CHF 20,000-40,000; hammer CHF 191,000. This adjacent-reference result is included for comparison with the 6510.

Antiquorum Geneva, Exceptional Horological Works of Art, 19 October 2002, Lot 37

6611 steel, École d'Horlogerie de Genève prize watch, c.1959, caseback engraved 1963. Antiquorum Geneva, 19 October 2002, Lot 37, CHF 50,600 hammer against CHF 25-30k estimate.

6611 stainless steel, École d'Horlogerie de Genève prize watch. Caseback engraved "Ecole d'Horlogerie de Genève – 1963" with the Rolex crown logo. Antiquorum describes the watch as one of six stainless-steel 6611 examples and says the small run was distributed as prizes by the École d'Horlogerie de Genève; the 1963 engraving dates the presentation, not the case manufacture. The lot card lists "circa 1959" for case production with the 1963 engraving for the school dedication; caliber listed as "1556, 26 jewels, Breguet balance spring" (a known Antiquorum cataloguing imprecision, since the underlying movement is the cal 1055B with Breguet overcoil and free-sprung Microstella). 36mm tonneau case fitted to a stainless-steel Oyster bracelet. Estimate CHF 25,000-30,000; hammer CHF 50,600. The cited lot is one documented example; the other five are not identified in the cited public record.

Auction context for 6510 specifically

The sources here contain two direct 6510 entries and several adjacent-reference comparables. They do not provide a complete auction census, production total, or reliable market history for the reference.

Two direct 6510 lots have surfaced at Antiquorum. "100 Years of Wristwatches," Geneva, 19 November 2000, Lot 258, sold a complete 18k pink-gold 6510: tonneau-shaped three-body case, matte silver dial with applied pink-gold indexes, radium-coated baton hands, cal. 1055. Estimate CHF 8,000-10,000; hammer CHF 12,075. It is a documented pink-gold case example. A second lot, New York, 30 September 2015, Lot 153, sold a bare cal. 1055 movement with dial and hands, catalogued jointly as "Ref. 6510/6511" because the movement alone cannot fix which case it came from; sold USD 2,500 against a USD 2,000-3,000 estimate. The joint cataloguing reflects that a loose movement cannot by itself distinguish the two case references.

Originals-era cluster, complete sub-reference roster

Reference	Period	Bezel	Bracelet	Movement	Notes
6510	1956–57	smooth / domed	Jubilee	cal 1055 (first generation, 7.0mm, gradual changeover, pre-SCOC dial)	The original. Subject of this article. Earliest documented case 134,636.
6511	1956–57	fluted	Jubilee	cal 1055 (first generation)	Parallel-launch sibling. Carries the fluted bezel that becomes the Day-Date signature. Phillips 2015 yellow gold lot above USD 205,000 anchor.
6611	1957–59	fluted	President (strongly associated; earlier fitment documented on a 6511)	cal 1055B (Microstella + COSC, 7.1mm)	Strong early President-bracelet association; the first Day-Date records show varied bracelet fitments. The 6611 carries the SCOC dial wording.
6612	1957–59	smooth	President	cal 1055B	Smooth-bezel sibling of the 6611. Phillips 2015 Lot 43 platinum diamond CHF 473,000 anchor.
6613	1957–59	factory diamond	President	cal 1055B	Factory diamond-set bezel sub-reference.
6611B	1958–59	fluted	President	cal 1055B with 0.1mm-thicker bridge plate	Late variant of the 6611. Movement-plate revision; external case stamped "6611".
6612B	1958–59	smooth	President	cal 1055B with thicker bridge plate	Late variant of the 6612. The "Lone Star" Arabic-script platinum sub-variant sits in this slot.

The published sources used for this page document the cluster through 6613, with the B-suffix bridge-plate variations as the later differentiation. That is a limit of the surviving source record, not proof that every unlisted number was never used. The 1803 / 1804 / 1806 / 1807 / 1811 cluster replaces the originals era from about 1959 onward.

The "Presidential" nickname, origin and dating

At launch the 6510 was marketed as the Day-Date or Oyster Perpetual Day-Date. The bracelet introduced with the 6611 was called the President in later Rolex and collector usage. Some evidence places the nickname in circulation by the late 1950s, while the better-known advertising association came later.

Lyndon B. Johnson's documented wearing of a yellow-gold 1803 helped connect the watch to the “President” name in the United States. The campaign date and the first use of the nickname are separate questions; neither should be used as a production date for a 6510.

The 6510 page therefore does not assign an unverified historical wearer to a specific watch. The better-documented political associations belong to later 1803 production.

Print bibliography

The principal print authorities on the Day-Date originals era:

• Mondani, Guido and Giorgia. Rolex Day-Date. Guido Mondani Editore, 2015. ISBN 9788894066951. 280 pages, 25.5 × 31.5 cm, multilingual (English / German / Italian). Limited edition 1000 copies. The first volume entirely dedicated to the Day-Date line.
• Gobbi, Paolo and Santinelli, Fabio. Day-Date, The Presidential Rolex. Spin Edizioni / Pucci Papaleo Editore, May 2015. 448 pages, 22 × 33 cm. 1000 original photographs, 160+ timepieces featured. Italian and English editions. Hardcover in slipcase.
• Goldberger, John. 100 Superlative Rolex Watches. Damiani Editore, 2008. ISBN 9788862080194. Documents the sibling platinum 6612 to the Phillips Glamorous Day-Date Lot 43 example.

Related references

• Day-Date 6511, 1956–1957
• Day-Date 6611, 1957–1959
• Day-Date 6612, Early President (1957–1959)
• Day-Date 6612B, 1957–1959
• Day-Date 1803, Fluted President (1960–1977)
• Day-Date 18028, 1977–1988

See also the Day-Date family index, movement reference, bracelet & clasp guide, and serial numbers by year.

Sources

• Rolex, history 1953–1967: Day-Date and President bracelet launch
• Phillips, 2015, lot 41: 6511 with President bracelet and clasp stamped 2.57

• The Vintage Rolex Field Manual, Colin A. White, Morning Tundra
• Stephen Pulvirent, "Everything You Need To Know About The Rise Of The Rolex Day-Date", Hodinkee
• Monochrome, "In-Depth: The History of the Rolex Day-Date, The Presidential Watch"
• Jake Ehrlich, "The Very First Rolex Day-Date", Rolex Magazine
• Swiss patent CH323982A, Marc Huguenin / Rolex Montres, 1955
• Rolex, Day-Date 36 brochure (President bracelet history)
• Rolex Day-Date Volume (Mondani Editore), Mondani Family, Guido Mondani Editore
• Day-Date, The Presidential Rolex, Pucci Papaleo Editore, Spin Edizioni, 2015-05
• Italian Watch Spotter editorial, "The History of the Rolex Day-Date", Italian Watch Spotter
• Sotheby's editorial, "The Rolex Day-Date: A Complete Collector's Guide", Sotheby's
• A Collected Man editorial, "The Colourful World of Rolex Stella Dials", A Collected Man
• Revolution Watches editorial, "The Stella Revolution", Revolution Watches
• Watchbase editorial, "Rolex Caliber 1556, Watchbase", Watchbase
• Bob's Watches editorial, "Quickset Vintage Day-Date Models", Bob's Watches
• Bob's Watches editorial, "History of Rolex Tiffany Dials", Bob's Watches
• Rolex Forums community, "Rolex Forums, 1803 Owners and Enablers Thread", Rolex Forums
• Vintage Rolex Forum community, "Vintage Rolex Forum, 1803 Threads (Tapatalk index)", Vintage Rolex Forum (Tapatalk)
• Phillips, "Rolex Ref. 6612, platinum and diamonds", Glamorous Day-Date, Geneva, 2015-05-08, Lot 43
• Phillips, "Rolex Ref. 6511, yellow gold", Glamorous Day-Date, Geneva, 2015-05-08, Lot 40
• Antiquorum, "Rolex Ref. 6611 steel, École d'Horlogerie de Genève", Geneva, 2002-10-19, Lot 37
• Antiquorum, "Rolex Ref. 6510, pink gold", 100 Years of Wristwatches, Geneva, 2000-11-19, Lot 258
• Antiquorum, "Rolex Ref. 6510/6511 movement lot", New York, 2015-09-30, Lot 153