Exercise:

When the Gregorian calendar was introduced in 1582,
the accumulated error in the Julian calendar was 10 days.
What was the error by the time the Gregorian calendar was adopted in Turkey, in 1927?

1600 was a leap-year in both calendars,
but 1700, 1800 and 1900 were not leap-years in the Gregorian calendar.
Thus the Julian calendar was 13 days adrift, by 1927.

Back to "calendars".