MATLAB Programming Fundamentals - MathWorks

Converting Date Vector Returns Unexpected Output

Because a date vector is a 1-by-6 vector of numbers, datestr might interpret your input

date vectors as vectors of serial date numbers, or vice versa, and return unexpected

output.

Consider a date vector that includes the year 3000. This year is outside the range of years

that datestr interprets as elements of date vectors. Therefore, the input is interpreted

as a 1-by-6 vector of serial date numbers:

datestr([3000 11 05 10 32 56])

ans =

18-Mar-0008

11-Jan-0000

05-Jan-0000

10-Jan-0000

01-Feb-0000

25-Feb-0000

Here datestr interprets 3000 as a serial date number, and converts it to the date string

'18-Mar-0008'. Also, datestr converts the next five elements to date strings.

When converting such a date vector to a character vector, first convert it to a serial date

number using datenum. Then, convert the date number to a character vector using

datestr:

dn = datenum([3000 11 05 10 32 56]);

ds = datestr(dn)

ds =

05-Nov-3000 10:32:56

When converting dates to character vectors, datestr interprets input as either date

vectors or serial date numbers using a heuristic rule. Consider an m-by-6 matrix. datestr

interprets the matrix as m date vectors when:

• The first five columns contain integers.


• The absolute value of the sum of each row is in the range 1500–2500.

7 Dates and Time