Here's what their dividend announcement said: "The Board has declared a cash dividend of $0.12 per NAT share which is one part of the dividend. The record date for the cash dividend is planned for February 20, 2014 and the payment is expected to take place on or about March 3, 2014.
In addition, the Board intends to declare a dividend composed of a portion of the shares that NAT owns in NAO. "
The way I read that, is that the board hasn't even declared the NAO shares part of the dividend yet, let alone set an ex-dividend date for it. Note the words "intends to".