Seiko 4S36

	Brand:	Seiko
	Family:	Seiko 4S Family
	Height:
	Jewels:	31
	Reserve:	50 hours
	Frequency:	28800 A/h
	Winding:	Automatic, Bi-Directional Automatic Winding
	Diameter:	25.60 mm (11.5 ligne)
	Complications:	24 Hour Hand, Date, Date by Pointer, Day, GMT Hand, Hacking Seconds, Hand Winding, Independently-Adjustable 24 Hour Hand, Power Reserve Indicator, Quick Date Correction, Quick Day Correction, Retrograde Day
	Hands:	Central 24 Hour Hand, Central Hour Hand, Central Minute Hand, Central Seconds Hand, Date Pointer at 6:00, Power Reserve Pointer at 9:30, Retrograde Day Pointer at 2:30

Distinguishing Technical Characteristics
Clockwise Balance Cock Screw Regulator Balance, Balance at 5:00
Production: 2007 – 2013
1910s	1920s	1930s	1940s	1950s	1960s	1970s	1980s	1990s	2000s	2010s	2020s

Cal. 4S36, made from 2007 through 2013, is perhaps the most complicated automatic movement ever produced by Seiko. Complications include retrograde day, date by pointer, retrograde power reserve indicator, and independently adjustable 24-hour hand. It was the final development of the Seiko 4S family, which itself was derived from the historic Seiko 52 stream of movements. Cal. 4S36 is similar in design to Cal. 4S76, though it lacks the upscale finishing and regulation of that movement. Unlike most 4S movements, Cal. 4S36 has 50 hour power reserve.

Unlike the related Cal. 4S27, which resembles a chronograph, this movement has a balanced look emphasizing the dual retrograde pointers on each side of the tall quadruple hand stack. A second crown at 2:00 on the dial adjusts the central 12 hour hand in 1-hour increments, leaving the stacked 24 hour hand as “home time.”

• A retrograde pointer at 2:30 shows the day on a “fan”
• A subdial at 6:00 shows the date using a small pointer
• A retrograde pointer at 9:30 shows the power reserve clockwise on a “fan”

Cal. 4S36 was used originally in the Seiko SARN “Luxury Power Reserve” watch series from 2007 through 2013. It also made a short appearance in The Seiko “Complicated” SAEN001 in 2012.

• 2012 Seiko Complicated SAEN001
• 2007-2013 Seiko Luxury Power Reserve SARN001
• 2007-2013 Seiko Luxury Power Reserve SARN003

Complicated Seiko 4S Movements

After 2000, Seiko had more diverse mechanical movements to choose from. The 4S family was moved upmarket as a base for modules to use in complicated upscale watches. The last 4S movement was retired in 2015.