Quite interesting - Mayan day/nights and earth periods

[Bring4th_Austin]

What about the transitional bodies?

The 3D portion of the body ceases to exist, and the 4D portion joins the rest of 4D, already in progress. Perhaps you are overlooking the fact that 4D is currently ongoing and populated, graciously refraining from physically manifesting itself before the cycle comes to an end.

63.14 Questioner: You are saying, then, that for the transition from third to fourth-density for one of the entities with doubly activated bodies, in order to make the transition the third-density body will go through the process of what we call death. Is this correct?
Ra: I am Ra. The third and fourth, combination, density’s body will die according to the necessity of third-density mind/body/spirit complex distortions.

Also

63.28 Questioner: Then are these entities of whom we have spoken, the third-density harvestable who have been transferred, the ones who then will, by bisexual reproduction, create the fourth-density complexes that are necessary?
Ra: I am Ra. The influxes of true color green energy complexes will more and more create the conditions in which the atomic structure of cells of bodily complexes is that of the density of love. The mind/body/spirit complexes inhabiting these physical vehicles will be, and to some extent, are, those of whom you spoke and, as harvest is completed, the harvested entities of this planetary influence.

This means these dual bodied individuals alive today will help produce 4D bodies by bisexual reproduction...dual bodies continue until they are evolved to 4D by reproduction.

Also, as Zenmaster pointed out earlier, "as harvest is completed" hints that harvest could be a process.