Assertion: calendar's month | /r/HasProperty | added
Facets:
Source sentences:
text: A month can either be added or omitted.
text: The ancient Roman Calendar added an extra month every few years to stay in sync with the seasons, similar to the Chinese leap month.
text: When the epact goes above 29 an intercalary month is added and 30 is subtracted.
text: A 13th month was added every six years to keep the calendar synchronized with the seasons.
text: Adjusting for this discrepancy, an extra month is added every two to three years.
text: Accordingly, the Jewish calendar adds an extra month (Adar II) every two or three years to compensate for the resulting 11-day lag.