Winter, in nature, is a time for hibernation, a time for rest, aligned with the Solstice.
Solstice comes from the Latin word solstitium and means the sun stands still.
December is also a time for celebrations in many cultures and religions with Christmas and New Year festivities.
Many years ago, when I was in England for Christmas, we received a gift ordered by a Spanish friend with the printed message on the card "Felices Siestas". The message was meant to be "Felices Fiestas" however the handwritten original message was misread, mistaking the letter "f" for an "s". An amusing anecdote which we still remember with affection at this time of year.
Wishing you all happy and restful holidays!