SpeedMaster Serial 85xxxxxx is it from 2009? ref 3220.50.00

You will never know the exact date of production on a modern Omega watch, not even within a year or two, based only on the serial number. A dated warranty card will of course give you an idea, but the watch could have been delivered years earlier. What I can say is that watch was officially discontinued sometime in 2012-2014, and they had likely stopped producing new ones even earlier — just kept it in the catalog until they sold out the old stock.

So 2009 is as good a production time as any. Could also have been 2005, or 2003. The important thing to you is that it likely has never been serviced — lots of people bought these because they the “cheap” Speedmaster of the era and then sold them when they realized how much a service was. And they continue to be sold/resold without service because the movement is tough and can continue working (albeit not as well as it should) even with little lubrication.

So, if you like the watch, consider having it serviced.