With spinoff, you generally have until the day of actual distribution to buy the stock and still receive the additional shares. Here's two examples where the ex-dividend date is the day of the distribution date (SEC law I believe), regardless of what date the PR says is the record date:
Just like a stock split, a record date is announced days or weeks ahead of the actual stock split, but you still get your shares if you're a buyer just the very day before. UWKI's PR says distribution date of the 20th so buyers on the 19th should still get the spinoff shares.
(no position at this time)
Raw
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