History of mathematics the Roman Kingdom and included 356 days plus a leap year every other year. In contrast, the lunar calendar of the Republican era contained 355 days, roughly ten-and-one-fourth days shorter than the solar year, a discrepancy that was solved by adding an extra month into the calendar after the 23rd of February. This calendar was supplanted by the Julian calendar, a solar calendar organized by Julius Caesar (100–44 BC) and devised by Sosigenes of Alexandria to include a leap day every four years in a 365-day cycle. This calendar, which contained an error of 11 minutes and 14 seconds, was
Burmese calendar will contain 354 days, as opposed to the solar year of ~365.25 days. Therefore, some form of addition to the lunar year (of intercalation) is necessary. The overall basis for it is provided by cycles of 57 years. Eleven extra days are inserted in every 57 years, and seven extra months of 30 days are inserted in every 19 years (21 months in 57 years). This provides 20819 complete days to both calendars. As such, the calendar adds an intercalary month ( ) in leap years ( ) and sometimes also an intercalary day ( ) in great leap years