See previous part.
Another way of explaining the pesukim about מִמָּחֳרַת הַשַּׁבָּת is that it never means "after the day of rest," that is, either after Saturday or after the first day of Yom Tov. That is, neither Chazal or the Karaites win this one. Rather, Shabbat always means "week". Let us examine the relevant psukim once again:
So the first and seventh days are holy convocations, in which one should do no manner of servile work, though there is a chol haMoed in between. How many days is that again? It is seven! And seven days make up a week!
If so, the day after the Shabbat is not the day after the first Yom Tov of Pesach (the first day), nor the day after the last day of Pesach (the seventh day). Rather, it is the day after the week of Pesach festival. This would be the eighth day. And it does not matter which day of the week it falls out on. Then, in the subsequent pasuk, when it says:
It refers to the day after this week of holy convocation. And then, it is not surprising at all when we encounter:
The Shabattot being complete must refer to weeks, not to Saturdays. And so it means weeks. Do we shift the meaning? Not according to the explanation I have suggested. This is another set of full weeks.