Seagull Caliber TY2871 Watch Movement

Manufacturer	Tianjin Sea-Gull
Caliber Number	TY-2871, TY2871
Base Family	ST16 (based on Miyota 8 series)
Movement Type	Automatic, self-winding mechanical
Lignes	11.5”’
Diameter	26mm
Height	6.57mm
Jewel Count	21
Beat Rate	21,600 bph
Lift Angle	46 degrees (unconfirmed)
Power Reserve	~36 hours
Rotor Winding Direction	Bi-directional (Magic Lever)
Hand-Windable?	Yes
Anti-Shock Device	Incabloc style
Hand Count	5
Functions	Central hours; central minutes; central seconds; double digit big-date at 12:00; pointer style day of the week subdial at 9:00; pointer style month subdial at 3:00; day/night indicator at 6:00 (sun and moon disc)
Hacking Seconds?	Yes
Country of Manufacture	Made in China (Tianjin city)
Known Models	(Add your watch to the comments below…)

The Tianjin Sea-Gull caliber TY-2871 is a triple-date automatic movement with a day/night indicator. This caliber is based on the ST16 family of movements.

As with most Made in China watch movements, technical documentation for the TY2871 is basically non-existent.