Christmas season

Short definition from Wiktionary

Noun

1. 1
   Advent, the period from Advent Sunday (inclusive) through the start of Epiphany.
2. 2
   Christmastide, Yuletide; the Twelve Days of Christmas, starting on Christmas Day and ending on Epiphany, January 6.
3. 3
   The winter season starting around Thanksgiving (typically Black Friday) and ending at or about New Year's Eve.
4. 4
   The period at the end of the year when retailers promote Christmas shopping opportunities