Julian calendar
WordNet
noun
(1) The solar calendar introduced in Rome in 46 b.c. by Julius Caesar and slightly modified by Augustus, establishing the 12-month year of 365 days with each 4th year having 366 days and the months having 31 or 30 days except for February
WiktionaryText
Noun
- The calendar which was used in the western world before the present-day Gregorian calendar. The Julian calendar differed in having all multiple-of-4 years as leap years.