I think the idea that’s being followed is these will be released at each equinox/solstice.
March/June/September/December
With the equinoxes being remix projects so samples in a month or so prior to release deadline.
The solstices are earmarked as original compositions and the deadline is usually given a month before.
Hope that’s useful info, and if I have my dates incorrect someone will be able to pitch in and I can edit the post.