December 31st, 1104 was a Saturday.
December 22nd, 1104 - January 20th, 1105
Why not celebrate an alternative birthday? In 404 days, exactly on September 3rd, 2027, people who were born on December 31st, 1104 will be 337,000 days old!
Fixed holidays (Christian feast day, New Year's Eve) which are celebrated on December 31st.
| M = 1000 | C = 100 | X = 10 | IV = 4 | I = 1 |
Yes: 1104 is a leap year, therefore has a 29th of February with an additional leap day and a total of 366 days (instead of the usual 365 days in a normal year).