Difference Between Gregorian and Julian Calendar Dates
Since the introduction of the Gregorian calendar, the difference between Gregorian and Julian calendar dates has increased by three days every four centuries:
| Gregorian range | Julian range | Difference |
|---|---|---|
| From 15 October 1582 to 10 March 1700 |
From 5 October 1582 to 28 February 1700 |
10 days |
| From 11 March 1700 to 11 March 1800 |
From 29 February 1700 to 28 February 1800 |
11 days |
| From 12 March 1800 to 12 March 1900 |
From 29 February 1800 to 28 February 1900 |
12 days |
| From 13 March 1900 to 13 March 2100 |
From 29 February 1900 to 28 February 2100 |
13 days |
| From 14 March 2100 to 14 March 2200 |
From 29 February 2100 to 28 February 2200 |
14 days |
A more extensive list is available at Conversion between Julian and Gregorian calendars.
This section always places the intercalary day on 29 February even though it was always obtained by doubling 24 February (the bissextum (twice sixth) or bissextile day) until the late Middle Ages. The Gregorian calendar is proleptic before 1582 (assumed to exist before 1582) while the Julian calendar is proleptic before year AD 1 (because non-quadrennial leap days were used between 45 BC and AD 1).
The following equation gives the number of days (actually, dates) that the Gregorian calendar is ahead of the Julian calendar, called the secular difference between the two calendars. A negative difference means the Julian calendar is ahead of the Gregorian calendar.
where is the secular difference; is the hundreds digits of the year using astronomical year numbering, that is, use (year BC) − 1 for BC years; and is integer division of H by 4. This truncates (removes) any decimal fraction (remainder) of the division, for both positive and negative numbers. Thus during the 1900s, 19/4 = 4, while during the −500s, −5/4 = −1.
The calculated difference increases by one in a centurial year (a year ending in '00) at either 29 February Julian or 1 March Gregorian, whichever is later. For positive differences, 29 February Julian is later, whereas for negative differences, 1 March Gregorian is later.
Read more about this topic: Gregorian Calendar
Famous quotes containing the words difference between, difference, julian, calendar and/or dates:
“To be honest, I knew that there was no difference between dying at their years old and dying at seventy because, naturally, in both cases, other men and women will live on, for thousands of years at that.... It was still I who was dying, whether it was today or twenty years from now.”
—Albert Camus (1913–1960)
“The difference between a healthy person and one who is mentally ill is the fact that the healthy one has all the mental illnesses, and the mentally ill person has only one.”
—Robert Musil (1880–1942)
“The rich were dull and they drank too much or they played too much backgammon. They were dull and they were repetitious. He remembered poor Julian and his romantic awe of them and how he had started a story once that began, “The very rich are different from you and me.” And how someone had said to Julian, “Yes, they have more money.””
—Ernest Hemingway (1899–1961)
“To divide one’s life by years is of course to tumble into a trap set by our own arithmetic. The calendar consents to carry on its dull wall-existence by the arbitrary timetables we have drawn up in consultation with those permanent commuters, Earth and Sun. But we, unlike trees, need grow no annual rings.”
—Clifton Fadiman (b. 1904)
“Nothing dates one so dreadfully as to think someplace is uptown.... At our age one must be watchful of these conversational gray hairs.”
—Ruth Gordon (1896–1985)