I'll cover all of the bases...
Beiwe Festival (Sami people of Fennoscandia)
Brumalia (Roman Kingdom)
Chawmos (Kalash people of Pakistan)
Christmas, Natalis Domini (4th century Rome, Christian)
Deygān, Maidyarem (Zoroastrian, Greater Iran)
Dongzhi Festival (East Asian Cultural Sphere)
Goru (Dogon people of Mali)
Hanukkah (Judaism)
Karachun (Ancient West Slavs)
Koleda, Коляда, Sviatki, Dazh Boh (Ancient East Slavs and Sarmatian)
Lá an Dreoilín, Wren day (Celtic, Irish, Welsh, Manx)
Lenæa (Ancient Greece and Hellenistic Greece)
Lohri (India)
Saint Lucy's Day, Lucia, St. Lucia (Scandinavia)
Makara Sankranti (Hindu, India and Nepal)
Maruaroa o Takurua, (Māori people, New Zealand)
Meán Geimhridh, Celtic Midwinter (Celtic, Ancient Welsh, Neo-druidism)
Midwinter (Antarctica)
Mōdraniht (Anglo-Saxon paganism)
Mummer's Day, Montol (Celtic, Cornish people)
Rozhanitsa Feast (12th century East Slavs, Russia)
Shab-e Chelleh, یلدا , Yaldā (2nd millennium BC Persian Empire, Iran)
Sanghamitta Day (Buddhism)
Saturnalia, Chronia (Ancient Greek, Roman Republic)
Şewy Yelda (Kurdish)
Sol Invictus Festival (3rd century Roman Empire)
Soyal (Zuni people and Hopi people of North America)
We Tripantu (Mapuche in southern Chile)
Yule (Finnic and Germanic peoples)
Zagmuk, Sacaea (Ancient Mesopotamia, Sumeria, Babylonia)
Ziemassvētki (Latvia, Baltic states, Romuva)
However and whenever you celebrate the Winter solstice, best wishes from RubiconAlpha!
