In western Christian tradition, January 6 is celebrated as Epiphany. It goes by other names in various church traditions. In Hispanic and Latin culture, as well as some places in Europe, it is known as Three Kings’ Day (Span: el Dia de los Tres Reyes, la Fiesta de Reyes, or el Dia de los Reyes Magos; Dutch: Driekoningendag). Because of differences in church calendars, mainly between the Eastern Orthodox and the western Catholic and Protestant traditions, both Christmas and Epiphany have been observed at different times in the past. Today, most of the Eastern Orthodox traditions follow the western church calendar. The exceptions are some Greek Orthodox Churches and related traditions (for example, Russian and Serbian Orthodox) that still follow the older calendar and celebrate Epiphany as the Theophany on January 19th.
Read the full essay, The Season of Epiphany, by Dennis Bratcher