Doris Day released her Christmas Album in Sept 1964 and it featured "Silver Bells".

The Supremes Christmas Album was released in November 1965 and it featured "Silver Bells".
Diana Ross' vocal styling on "Silver Bells" sounds similiar to Doris Day's version. Any thoughts?

Why was The Supremes Christmas Album released so late in the holiday season. Most people start Christmas Shopping directly after September's Labor Day.
The Doris Day holiday album was released at an appropriate time for maximum potential sales volume. Any thoughts?