squeak: Going with your pshat, how is it that it is still mutur to kill (what we call) lice on Shabbos?
646: The 6 days of creation were in fact 24 hours. How could they not be? Aren’t days 24 hours now? So when did this change? Where does it indicate in the slightest that the first Sunday after creation (or the first Shabbos) was suddenly shorter than previous days?
On the contrary – it’s clear that on the fourth day Hashem said the sun should shine during the time-period that was called “day” and the stars/darkness should rule during the time-period called “night”. Since then, that hasn’t changed, and obvisouly, as we can see today, the sun and the stars have decided that the time period called day plus the time period called night, are 24 hours.