I suspect the authors intention here was to present a simplified calendar with some nice guarantees (e.g. dates matching days), not a lunisolar alternative. The

I suspect the authors intention here was to present a simplified calendar with some nice guarantees (e.g. dates matching days), not a lunisolar alternative. The Positivist calendar ignores the lunar cycle to reduce complexity that others have in spades, including both the Gregorian and the Hebrew calendars.