Omega is a Swiss watch company that was founded in 1848. Omega is owned by the Swatch Group. The Omega Seamaster is made to be a deep diving watch and some models feature a second crown that releases helium after diving. The Seamaster has been worn by James Bond since 1995. The automatic Seamaster winds itself automatically when worn or placed in a watch winder. It can be manually wound but it is not necessary to do this.
Turn the crown counterclockwise to unscrew it. The crown should pop out when it is unscrewed. When the crown pops out it is in the "neutral" position. If you turn the crown clockwise in the "neutral" position you can manually wind the watch.
Pull the crown out one notch. Turn the crown clockwise to change the date. This is how you change the date on "quickset" date Omega watches. All modern Seamasters have the "quickset" date function. Some vintage Seamasters have the "quickset" but others have the pump style. For pump-style Seamasters pull the crown out to the last notch and pump the crown in and out to change the date.
Push the crown in and simultaneously turn it clockwise to tighten it. The crown should be tight to ensure that the case is waterproof.
Do not change the date of the watch between the hours of 8 p.m. and 2 a.m., because the date is automatically changing during these hours.