Lughnasa is an Irish word meaning the month of August In modern Irish it is spelled Lúnasa. It celebrated on August 1st, it marks half way between the Summer and Autumn equinox. Lughnasa is the beginning of the harvest season.
The Celtic Calendar was and is still used by the Celts - in Ireland, Scotland and the Isle of Man. Like any Calendar - it divided up the year into natural cycles. The Celtic Calendar Wheel is based on the connection the Celts had to the Earth. It is dictated by the seasons, the darkness and the light.