Winterval?

My BIL in Virginia is confused when we use the term 'holidays' and he always tries to correct us using  'The Holiday season'  or 'Happy Holidays!'. SIL, a Kiwi, always defends us saying she couldn't understand why such a fuss was made of being pc. The holidays in December are the Christmas Holidays as far as we're concerned!  ..... Mere Kirihimete! - Merry Christmas!