tf = isnat(A) returns an array the same
size as the datetime array, A, containing logical 1
(true) where the elements of A are
Not-a-Time (NaTs) and logical 0 (false) where
they are not. NaT represents a datetime that is undefined.
You can also select a web site from the following list
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.