December 29th, 1220 was a Tuesday.
December 22nd, 1220 - January 20th, 1221
Why not celebrate an alternative birthday? In 771 days, exactly on September 4th, 2028, people who were born on December 29th, 1220 will be 295,000 days old!
Fixed holidays (Christian feast day) which are celebrated on December 29th.
| M = 1000 | C = 100 | X = 10 | IX = 9 | I = 1 |
Yes: 1220 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).