Christmas season

noun
RareNot in standard dictionaries
1

Advent, the period from Advent Sunday (inclusive) through the start of Epiphany.

2

Christmastide, Yuletide; the Twelve Days of Christmas, starting on Christmas Day and ending on Epiphany, January 6.

3

The winter season starting around Thanksgiving (typically Black Friday) and ending at or about New Year's Eve.

4

The period at the end of the year when retailers promote Christmas shopping opportunities

#informal