Even with Mercedonius, the Roman calendar eventually became so far off that Julius Caesar, advised by the astronomer Sosigenes, ordered a sweeping reform. 46 B.C. was made 445 days long by imperial decree, bringing the calendar back in step with the seasons. Then the solar year (with the value of 365 days and 6 hours) was made the basis of the calendar. The months were 30 or 31 in length and to take care of the 6 hours, every fourth year was made a 366 day year. Moreover, Caesar decreed the year began with the first of January, not with the vernal equinox in late March.
This calendar was named the Julian Calendar, after Julius Caesar and it continuous used by the Eastern Orthodox churches for holiday calculation to this day. However, despite the correction, the Julian calendar is still 11 and one-half minutes longer than the actual solar year, after a number of centuries, even 11 and one-half minutes adds up.
The Roman Calendar
The
Ancient Roman Calendar
In
Roman Calendar, it consist of 10 months only. 6 months of 30 days and 4 months
of 31 days. But they used it only in a matter of time. Romans
changed their calendar around 47 B.C. They called it Julian because of the name
of Julius Caesar
Martius --------------------------------------------------- 31
Aprilis ------------------------------------------------------ 29
Maius ------------------------------------------------------ 31
Lunius ------------------------------------------------------ 29
Quintilis ---------------------------------------------------- 31
Sextilis ------------------------------------------------------- 29
September -------------------------------------------------- 29
October ------------------------------------------------------ 31
November --------------------------------------------------- 29
December --------------------------------------------------- 29
Ianuarius -----------------------------------------------------29
Februarius ---------------------------------------------------28
Februarius (leap year) ------------------------------------23
Intercalaris (leap year) -----------------------------------27/28
SOURCES:
Ellis,Elizabeth G. “Prentice Hall
World History” The Asian Foundation
Philippines, Book for Asia. C 2009
Zaide, Gregorio F. “Kasaysayan
Ng Daigdig” Quezon City: All Nation
Publishing Co; INC. C 2002
___________ “On Egyptian and
Roman Calendars” The World
Book Encyclopedia, Vol. 3, USA: World
Book Inc. C 1997.
Johnson, Van L. “The Roman Origins
of Our Calendar” USA: American Classical
League, C 1974
Ellis,Elizabeth G. “Prentice Hall
World History” The Asian Foundation
Philippines, Book for Asia. C 2009
Zaide, Gregorio F. “Kasaysayan
Ng Daigdig” Quezon City: All Nation
Publishing Co; INC. C 2002
___________ “On Egyptian and
Roman Calendars” The World
Book Encyclopedia, Vol. 3, USA: World
Book Inc. C 1997.
Johnson, Van L. “The Roman Origins
of Our Calendar” USA: American Classical
League, C 1974