Lughnasadh is commonly celebrated on the 1st of August. It comes halfway between the summer solstice and and autumn equinox. Many now ovserve it on the Sunday closest to the 1st, while others wait until the full-moon nearest the day. In 2014 the closest full-moon was on 10-August, while in 2017 it will be 7-August.
The nearest full-moon dates from 2012 through 2020 are...
From Wikipedia you will find the following of interest...
"Lughnasadh is mentioned in some of the earliest Irish literature and has pagan origins. The festival itself is named after the god Lugh. It involved great gatherings that included religious ceremonies, ritual athletic contests (most notably the Tailteann Games), feasting, matchmaking and trading. There were also visits to holy wells. According to folklorist Máire MacNeill, evidence shows that the religious rites included an offering of the 'first fruits', a feast of the new food and of bilberries, the sacrifice of a bull and a ritual dance-play in which Lugh seizes the harvest for mankind and defeats the powers of blight. Much of the activities would have taken place on top of hills and mountains."
"Lughnasadh customs persisted widely until the 20th century, with the event being variously named 'Garland Sunday', 'Bilberry Sunday', 'Mountain Sunday' and 'Crom Dubh Sunday'. The custom of climbing hills and mountains at Lughnasadh has survived in some areas, although it has been re-cast as a christian pilgrimage." (A common tactic of christians is to try to take over sacred pagan days and turn them into something related to their christ.)
It is also seen as a day where trial marriages were conducted. The trial marriage lasted a year and a day, at which time the marriage could be made permanent or broken without consequences.
In the Wiccan practice, it is seen as one of the two best times for handfasting, the other being at Beltane.
Some Wiccans mark the holiday by baking a figure of the "corn god" in bread, and then symbolically sacrificing and eating it.
So mote it be.
High Priest and Magus
The Liberated Of Lucifer