MATLAB: Problem with input for the datetime function

cell arraydata typesdatetimestrings

I have a cell array containing strings that describe a date. It looks like this:
datum=
'01.06.2014'
'02.06.2014'
'03.06.2014'
'04.06.2014'
'05.06.2014'
I want to convert them to a Matlab recognised date array, so that I can ultimately determine in which Calender Week they fall in (using the function week)
My code looks like this:
%reading in the data file and isolating the weekday column
dateiname='ABGERUFENE_SRL_BETR_IST-WERTE_20140601_20140630_Netzregelverbund_20150408-225302.CSV';
[num text raw]=xlsread(dateiname);
raw([1 2 3 4 5],:) = [];
datum=raw(:,1)
%conversion into date
datum=datetime(datum, 'InputFormat','dd.mm.yyyy');
However this returns the error message: ??? Undefined function or method 'datetime' for input arguments of type 'cell'. It should be able to handle a string, so I don't understand the problem. I have used the query
iscellstr(datum)
which returns a 1, so I really don't know why the error appears. I have also tried using the "text" data – that doesn't work either.
Any help troubleshooting will be much appreciated!!!!!

Best Answer

datetime was released in R2014b so if you're using an earlier release, you'll need to upgrade to use it.
This works fine for me in 15a (though you need to use MM instead of mm months instead of minutes).
datum=datetime({'08.07.2015'}, 'InputFormat','dd.MM.yyyy');