We deduce the idea that there is a count from eight times 36 plus a "day". However, that count adds up to 5790 when Bina "falls", ם to ת. That is not the beginning, in time, as Chochma "falls" first, ץ to צ, in 5786.
So our count is wrong, in a sense. Which count shall we institute, then? The count that is based on a Cosmic Number, which ends in 5786.
Now, I don't say that the GR"A reasoned this way. But he could have, with help of the Divine.
