Changes

by Cormac, O'Donovan, John, ed. and tr; Stokes, Whitley, 1868)</ref><ref name="Olmsted">Olmsted, Garrett (2009). ''The Coligny Calendar: the Implications for Gaulish and Irish Festival Dates''.</ref>  

by Cormac, O'Donovan, John, ed. and tr; Stokes, Whitley, 1868)</ref><ref name="Olmsted">Olmsted, Garrett (2009). ''The Coligny Calendar: the Implications for Gaulish and Irish Festival Dates''.</ref>  

A Celtic lunisolar calendar has been reconstructed from fragments of two first century BC calendars found in the French towns of Coligny and Villards d'Heria. The first month on this calendar is called ''Samonios''. The name is cognate to Samhain. The Celts celebrated a three-day festival that began on the 17th of ''Samonios'', according to the calendar.<ref name="Olmsted"/>

A Celtic lunisolar calendar has been reconstructed from fragments of two first century BC calendars found in the French towns of Coligny and Villards d'Heria. The first month on this calendar is called ''Samonios''. The Celts celebrated a three-day festival that began on the 17th of ''Samonios'', according to the calendar.<ref name="Olmsted"/>

With a leap day every five years, the Coligny calendar gives the length of a solar year as 365.20 days. Since the true length is 365.2422 days, the calendar drifted by one day every 23.7 years.<ref name="Olmsted"/>

With a leap day every five years, the Coligny calendar gives the length of a solar year as 365.20 days. Since the true length is 365.2422 days, the calendar drifted by one day every 23.7 years.<ref name="Olmsted"/>