This is a classic case design from Bulova. It is a 1970 Bulova Accutron Date & Day. I do not know the variant but believe this to be an International Model.
In reply to This is a classic case… by JimDon5822
My error. There is no Day so this is a Bulova Accutron Calendar.
Don't see this beauty in any of our line books (catalogs) 1970 Bulova Accutron Calendar
Love that this watch is engraved, very old school at this date.
1970 Bulova Accutron Calendar
I also agree this is likely an internationally produced and marketed watch based on the s/n starting with "3 -". Best ID I can give is
1970 Accutron Calendar
This watch was most likely bought in Finland, it belonged to my father and he got it as graduation present.
So it is probably an "international model" as mentioned above.