The Chuseok holiday of Korea originated from the Ga"bae(嘉排) holiday of the ancient Shilla dynasty. But there might be some problems in directly connecting the Chinese Jungchu(中秋) holiday, which was essentially a holy service for the moon, with the Shilla Ga"bae holiday.
Ga"bae celebration first appeared during Shilla king Yu"ri-wang"s reign. For an entire month, under the lead of two female members from the royal family, who also served as female priests, civilian females were specially recruited from the Six Bu units, in order to support the royal priests. Two teams were formed, and continued "weaving"(the "Jeok"ma" ceremony) in a form of a contest, and after the competition was ended they would present such products to the holy spirits through a memorial service, which was called the "Bu"jeong-je(部庭祭)" service.
We believe the Ga"bae celebration was a festival that followed such task and service. The participants consisted of the royal females who led the two teams, and the civilian females from the Six Bu units who formed two groups and competed with each other. We can say that the Ga"bae festival was in fact a female festival. The place for this event, which was referred to as "Dae"bu"ji-jeong(大部之庭)" was not an ordinary space. It was a place for a holy religious activity, and also a sacred place for the Bu"jeong-je service.
But according to the "Memorial Services" chapter of 『Samguk Sagi』 , the Bu"jeong-je service was not considered as a Confucian-style memorial service held at the Dynastic shrine or the founder king"s mausoleum. And it seems it was also different from other Shilla-specific services too. It could have been a service that belonged to the category of Miscellaneous Services("Jab-sa, 雜祀").
If it was indeed a traditional, folklore-based service, then it must have been a customary ritual designed to serve the objective of the royal family through a spiritual act of communicating with God. So, a Shaman priest(巫覡) with a specialized talent in the area would have led the services sometimes as well. Not only the two royal family females who led the contest and the service, but also the other females who were drafted from the Six Bu units, might have been selected to become part of a larger priest group.
They must have taken on a variety of roles, but mostly they would have been ordered to weave textile products which were to be used in the Bu"jeong-je service, or to make clothes for the holy spirits(神衣) and enshrine them. Interestingly, the object to be receiving the service, and the subject who was arranging the holy memorial service, usually were regarded as one, as it was the general perception that the holy spirit would come down and superimpose itself upon the priest who was offering the service. In other words, the holy spirit overseeing the task of weaving was a female god, and a female priest serving that female God was literally offering the results of weaving.