Now available at auction from Second Vintage The Seikomatic Weekdater stands as a brilliant testament to Seiko’s mid-century design ingenuity, offering a sophisticated and highly legible approach to the day-date complication. Characterized by its distinctive separation of the day and date apertures, this timepiece elegantly displays the day of the week in a prominent window at the six o'clock position, creating a beautifully balanced and symmetrical aesthetic. As a premium automatic offering from the 1960s, the Weekdater encapsulates the golden era of Japanese watchmaking, combining robust mechanical performance with a refined, executive presence. Brand: Seiko Model: Seikomatic Weekdater Reference Number: 6206-8990 Serial Number: 4601365 Movement: Automatic Caliber 6206A, 26 Jewels Dial: Silver sunburst dial with applied gold-tone faceted indices, exhibiting visible age-related spotting and authentic patina. Case Size: 37 mm (excluding the crown) Case Material: Gold Plated (EGP) Production Year: June 1964 Condition: Good vintage condition, displaying honest wear and authentic aging. Dial and Hands The silver sunburst dial features a striking layout defined by its separated calendar complications, with a gold-framed date window at three o'clock and a prominent, stepped day aperture at six o'clock. Applied gold-tone faceted indices with black central stripes provide excellent contrast and depth. The dial exhibits clear signs of its vintage journey, with visible spotting, minor discoloration marks, and age-consistent patina present across the sunburst surface and around the outer edges. The applied Seikomatic gyro logo remains crisp and well-defined. The time is indicated by gold-tone dauphine hands featuring pale, evenly aged luminescent inserts, complementing the overall vintage character of the display. Case and Crystal The 37 millimeter gold-plated case features classic mid-century proportions with sweeping lugs and a seamlessly integrated recessed crown positioned at four o'clock. The case exhibits heavy, honest signs of wear, with significant fading and brassing to the gold plating, particularly along the lug edges and case flanks where the underlying metal is clearly exposed. The lug profiles have softened over time, reflecting decades of handling and use. A domed acrylic crystal protects the dial, maintaining the smooth, curved profile characteristic of the era. The snap-on caseback features a finely engine-turned interior perlage finish, marked with the EGP designation and reference numbers. Movement Powering this timepiece is the Seiko Caliber 6206A automatic movement, featuring 26 jewels and a rich gold-tone finish across the rotor and bridges. The movement presents cleanly, with the factory engravings proudly displayed on the winding weight. Running in vintage operational condition. Maintains the authentic mechanical character of the era. Timegrapher results indicate +48 to +50 seconds per day. Strap The watch is fitted with a dark brown embossed leather strap featuring contrasting reddish-brown stitching. The strap shows visible signs of wear, creasing, and aging, pairing well with the worn-in, vintage aesthetic of the gold-plated case. It is secured with a gold-tone pin buckle. Condition This Seikomatic Weekdater is presented in good vintage condition, offering a highly authentic and unpolished appearance. The dial shows noticeable spotting and patina, while the gold-plated case exhibits heavy brassing and edge wear. These elements combine to tell the story of a well-worn, well-loved mid-century timepiece that retains its fundamental charm and mechanical integrity. Dimensions The case measures 37 mm in diameter, excluding the recessed crown, providing a substantial yet elegant footprint on the wrist that remains highly wearable by modern standards. Remarks For collectors of vintage Japanese horology, the Weekdater layout remains one of Seiko's most charming and distinctive calendar designs. The prominent six o'clock day display offers a level of visual balance that is rarely seen in standard day-date configurations. Despite its cosmetic wear, this example offers a wonderful opportunity to acquire a mechanically fascinating piece of Seiko's storied history. History Introduced in the 1960s, the Seikomatic line represented Seiko's push into producing high-quality, reliable automatic timepieces for the modern professional. The Weekdater variant, with its unique separated calendar display, quickly became a favorite for its legibility and balanced dial symmetry. It served as a precursor to many of the advanced day-date designs that would follow, cementing Seiko's reputation for innovative and practical complications during a period of rapid technological advancement in Japanese watchmaking. Payment and Shipping Payment must be completed within 1–3 days after purchase. Your watch will be professionally and very securely packaged, and shipped with tracking and insurance for your peace of mind. We ship via fast express service, with typical delivery in 1–4 business days (destination dependent). Note that with vintage watches, minor signs of wear, aging, or imperfections may be present and are considered normal for watches of this age. Please review all photos carefully before bidding. We strive to photograph each watch from multiple angles for the most accurate representation. The photos form an important part of the description. If there are any concerns of functionality or defects after delivery, make sure to contact us within 3 days of receiving the watch so we can assist you. As with all vintage watches, water resistance is not guaranteed. If you have any questions, feel free to contact us after the auction ends. / Second Vintage SKU: SEI-SMW-0010