Cal. 4S76, made from 2004 through 2010, 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. 4S76 is similar in design to Cal. 4S36, though with upscale finishing and regulation for use in Credor watches. Unlike most 4S movements, Cal. 4S76 has 50 hour power reserve.
Unlike the related Cal. 4S77, 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. 4S76 was used the Credor Node GCBT and GBBT watch lines from 2004 through 2010.
- 2004 Credor Node GBBT999
- 2004-2009 Credor Node GBBT998
- 2007-2010 Credor Node GBBT994
- 2004-2006 Credor Node GCBT999
- 2005-2009 Credor Node GCBT998
- 2004-2008 Credor Node GCBT997
- 2004-2007 Credor Node GCBT995
- 2004-2010 Credor Node GCBT993
- 2007-2009 Credor Node GCBT989
- 2007-2010 Credor Node GCBT987
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.
| Production | Watch | Winding | Jewels | Notes | |
|---|---|---|---|---|---|
| 4S27 | 2003-2007 | SAGN | Automatic | 28 | Retrograde day at 2:00 Date pointer at 6:00 GMT subdial at 9:00 |
| 4S29 | 2003-2007 | SAGN | Manual | 29 | Small seconds at 6:00 Retrograde power at 9:00 |
| 4S36 | 2007-2013 | SAEN SARN | Automatic | 31 | Independent 24 hour hand Retrograde day at 2:00 Date pointer at 6:00 Retrograde power at 9:00 |
| 4S76 | 2004-2010 | GBBT GCBT | Automatic | 31 | Independent 24 hour hand Retrograde day at 2:00 Date pointer at 6:00 Retrograde power at 9:00 |
| 4S77 | 1996? 2000-2005 | GCBG | Automatic | 28 | Retrograde day at 2:00 Date pointer at 6:00 GMT subdial at 9:00 |
| 4S79 | 1998-2015 | GBAY GCAY | Manual | 31 | Small seconds at 6:00 Retrograde power at 9:00 |