‘scholar’:
somewhat bemused that this matter has escaped the attention of critics such as COJ.
It’s unlikely that it escaped his attention, but as he was responding to the claims made in the Watchtower articles, and those articles avoid mentioning the solstice, it was possibly out of scope. But a Google search finds that the correct date of the solstice has indeed been mentioned previously. In any case, the issue with the solstice exists independent of any tedious fallacious arguments from authority or incredulity.