Definitions for "ex-date"
For stock splits, the date that the share price changes to reflect the split.
In terms of stock splits, this is the day that the stock price adjusts to reflect the issuance of new shares as the result of the stock split.
The cutoff date when the right to receive a declared stock dividend does not automatically transfer from the seller of a security to its buyer. The ex-date is also known as the ex-dividend date.