Seiko, founded in 1881, produces mechanical and quartz watches, along with clocks and other electronic devices. Seiko Clock Inc. is a subsidiary of the Seiko Corporation and well-known for products such as the first talking quartz clock. Other Seiko clocks include the handcrafted decor series, such as the Aegean and Galileo. Seiko clocks have high timekeeping accuracy, but there may be instances when you need to adjust the clock speed. For digital models, you cannot adjust the time speed, but you can reset the clock entirely. For pendulum, wall and mantle clocks, you need to adjust the speed manually.
Set the current time by turning the setting knob counterclockwise, until the hands exactly match an accurate timepiece. For wall clocks, hang the clock levelly back on the wall and listen for the pendulum beat. Adjust the bottom of the clock slightly to the left or right until the beat sounds even.
Check the clock against the accurate timepiece 12 and 24 hours later. Note whether your Seiko clock is running slow or fast.
Find the adjustment mechanism. For Seiko wall clocks, this is a wheel or nut underneath the pendulum bob. For mantle clocks, this is an adjustment wheel on the clock's face.
Stop the pendulum. Hold the rod gently and turn the adjustment wheel to the left to speed up the time, or to the right to slow it down. Wind your clock and set the pendulum swinging again by moving it to the left with your hand and then letting go.
Monitor your clock's time over the next few days, checking it against the accurate timepiece. Adjust and rewind as necessary, until your clock is within one minute of the correct time.
Place your mantle clock on a smooth, level surface for accurate timekeeping. Slamming doors or opening and shutting desk drawers may affect the speed. Hang your wall clock with a strong bolt or screw to sufficiently support its weight. This will ensure a smooth pendulum swing.