The origin of Halloween is firmly rooted in the pagan beliefs of long ago. Halloween started out as Samhain, or the New Year, of the Celts in 5th century BC. Originally celebrated on October 31st, it was the third and last harvest for the year. It was also the time of death for the pagan god, although this god was re-born at Yule. This was the day that summer officially ended. The sun, measured by ancient standing stones in Ireland and Britain, is at its lowest point on October 31st. It is believed that this is why the Celts chose this day to be their New Year.