New Years in the First Terran Empire
In the First Terran Empire, each year's end was marked by back-to-back holidays, Yulstice and Year Day.
Yulstice, the final day of the old year, was also known as Santamas and was celebrated by the arrival of Santa, a jolly old elf who brought presents to good children and turned bad children into carbon.
At midnight on Yulestice, synchronized crystalline balls dropped on major Imperial worlds, while everyone toasted the new year with their libation of choice.
Year Day, the first day of the new year, was celebrated by parties
Both these holidays were intercalary, i.e. they were independent of the pattern of tendays. The preceding day (December 30) always fell on Terraday, a traditional day off. The succeeding day (January 1) always fell on Sunday, also a traditional day off.
The result was a four-day holiday enjoyed by all.
Many societies that came after the Empire preserved the same calendar and the same four-day year-end holiday.