convert time stamp into minutes or seconds

I have a file with

29.06.2014   09:53:37      -1.8
29.06.2014   09:58:36      -2.0
29.06.2014   10:39:01      -2.0

I would like to covert the second column into how long time past from the first readout in the column, in minutes or seconds and plot column 2 and 3. Matlab doesn't seem to be able to handle the ':' sign. How do I do this?

Many thanks!

Answer 1

[Jos (10584)]

I assume the 3rd column represents a value.

[D,T,V] = textread('MyFile.txt','%s%s%f')
DT = datevec(strcat(D,'-',T),'dd.mm.yyyy-HH:MM:ss') % convert to matlab time vectors
dTsec = arrayfun(@(k) etime(DT(k,:),DT(1,:)),1:size(DT,1)) % relative time in seconds

Answer 2

[David Sanchez]

Take a look at this thread, it deals right with your problem.

http://www.mathworks.com/matlabcentral/answers/108833-read-time-with-colon-from-txt-file