That dividend is incorrect. The last dividend was on Oct 23 and was 0.00374772 BTC/share.
What you are looking at is likely
the sum of all dividends paid previously.That's exactly what it is. If you click on the cell it shows that it is the sum of the entire column [=SUM(L1:L986)]
Why they pay the dividends on Sunday instead of Wednesday.
They didn't, it's just the bottom of that column happens to line up with row Oct. 27. It means nothing but the sum of the dividends column.