Green[County Court returns] William, m. Elizabeth Wheeler. Capt. Marshall. 13 (7) 1659.[Note: In old-styles dates, the seventh month is September. More info may be found here.]
Vinton says 13 Sep 1659 comes from Middlesex County records, and 13 Mar 1659-60 comes from the Malden records, "both being copies of a perished original". Several sources simply report both dates without providing any explanation, e.g., Source:Newhall, Charles Lyman. Record of My Ancestry and Source:Cutter, William Richard. New England Families, Genealogical and Memorial, while some seem to pick one, e.g., Source:Wheeler, Albert Gallatin. Genealogical and Encyclopedic History of the Wheeler Family in America.