Chris said: "...to be clear, this is a 24-hour limit not a calendar day limit that clears at midnight in some time zone". (Text formatting not in his post)
It remains to be seen if he meant to imply the 24 hour limit was not supported within all zones.
As you initially said and maintain, there is something about WikiTree and time zones that, in your experience, appears to be inconsistent with our reasonable expectation. If such an anomaly exists, might it influence anyone's monthly contributions count?