The Grandfathers' Moon Festival is a conjoined holiday festival celebrated in certain parts of the world, most recently brought over into Equestria by Wind Cheer.
The first date of celebrating the Grandfathers' Moon is set to 1st of October, 16:00 Equestrian Standard Time. All festives will be held at the Sweet Apple Acres.
The Holiday's Celebration[]
Mainly a form of harvest festival, the Grandfathers' Moon is celebrated together with closest friends and family, though the definition of 'closest' varies from pony to pony. Gathering together at the proprietors' land, it's customary to bring their own food - not for consumption, but for offering to both the ancestral spirit and the Moon itself.
The celebrations themselves are not especially noteworthy. The revellers are expected to decorate their houses and neighbourhood in still-green grass and candles, usually formed into miniature 'shrines' or small ensembles to fit the setting. Occasionally, said grass is also attached to walls of one's home, or woven and hanged from linen ropes in the air. Lanterns may or may not be present, though they are certainly a good touch.
Finally, the host of the party is expected to supply food and drink for all the guests. These vary, yet rice or potato dumplings are almost universally present. Green tea or extremely-lightly salted water also make an appearance, the later solely for use by the adult mares and stallions, though exceptions apply.
Midnight's Whimsy Haunt[]
All that said, the real meat of the Grandfathers' Moon begins after nightfall, when the full moon is at its brightest. Legend has it that on this day, the spirits of the long-forgotten stir and wake. Thus, ponies greet them again into this world by offering food, song and dance. In practise, however, this is done by commanding a mandatory minute or two of silence as nature's sounds run their course. Afterwards, food and drink is deployed to its fullest and the revelling ponies can finally enjoy themselves throughout the long night.
Origins[]
Truth be told, the name "Grandfathers' Harvest Moon" is actually an agglomeration of two pre-existing festivals, merged into one on liberal behalf of the aforementioned pony.
The real traditions are called the "Grandfathers" and "Moon Viewing Festival" respectively, with both originating across the eastern Equestrian border.
The first holiday, "Grandfathers" ('Dziady' in the native tongue) is a middle-eastern Old Kingdom celebration held upon the end or in the middle of typical harvest. Getting together with friends and family, the ponies celebrate with and thank their ancestors for a bountiful harvest, hence the name. While technically forgotten to the modern world, much of the tradition has been incorporated into the "Souls' Day" back in the old world.
The second holiday, "Moon Viewing Festival" is celebrated in far-eastern Haysia. As mentioned above, ponies gather to feast and drink while enjoying the sight of the full moon. It is said that Princess Luna herself has made the moon shine especially bright for this celebration. How much of the legend is truth remains to be revealed. The Moon (and/or the Princess) is also thanked for the good harvest the celebrated year.