December 31st, 1340 was a Saturday.
December 22nd, 1340 - January 20th, 1341
Why not celebrate an alternative birthday? In 602 days, exactly on March 19th, 2028, people who were born on December 31st, 1340 will be 251,000 days old!
Fixed holidays (Christian feast day, New Year's Eve) which are celebrated on December 31st.
| M = 1000 | C = 100 | XL = 40 | X = 10 | I = 1 |
Yes: 1340 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).