This is from the following section on divvies > 25%:
It doesn't matter to us "how" NASDAQ determines the ex-date (two days before, etc); all we can go by is that they *do* determine the ex-date and cause it to be published on the daily list.
And, clearly, as emphasized in the notice to brokers, the ex-date prevails.
It's not the stick-their-noses-into-our-business DTCC that prevails--their job is to manage delivery, NOT interpret filings.
You might try this, too, as an alternative to filing a complaint against the broker: