Antique dating pocket swiss watch
It will NOT tell you the actual date the watch was acquired...
The "New Haven" was dated by looking at the style of the watch. Notice that the watches from the early 1930's still have engraved cases.
Note the thick hands, engraved patterns and bold design of all of these watches.
These watches are typical of the "Deco" style of the teens and 20's.
If you don't know what your watch is, there's no possible way to know what it's worth.
If you're buying or selling a car, it's not enough just to know that it's an old Ford.