Automatic Winding Movement —
an Automatic watch operates with the same principle as a mechanical manual wind watch - with the addition of a weighted pendulum called the "Rotor". The Rotor is attached to the back of the movement, and when the watch is in motion (with regular wear) the rotor spins around the inside of the watch & "automatically" winds the watch, thus eliminating the need to constantly manually wind the watch. It is important to understand that automatic watches also require a manual wind every so often. An automatic watch that has stopped or is at the end of its power reserve due to non-wear should be manually wound 30-40 times. Manually winding an automatic watch after the power reserve has ebbed or the watch has stopped ensures the watch is at full reserve when first worn, so as long as the watch is worn it will remain fully wound. When removed the watch will stay working for the specified amount of time as indicated in your manual (generally 35-45 hours).