I would say 1.23b will be end of Sept - start of Oct, mid Oct would give us no time to run any content they give us.

I think it will also include the end of the world things, and they will be time activated so for example on xxx day aethers start to get pulled up, another day meteors might start falling, and finally Dalamud falls on us, and we have to sacrifice Lalafell to send us forward in time and save our skins.