String plot of data read from text file

I need to plot a graph of a certain value against date/time. Now i am getting values from a text file which are time stamped and i need to use those dates. So when I extract the required data its in form of string and i am not able to plot. Can anyone kindly help me out. Code is as follows :

clear;
clc;

%read data at start of program for calibration

      io_contents = fullfile('Average Reflex Time.txt'); %File directory

      filetext = fileread(io_contents); %Read contents of file

      expr = '\A'; %extract data
      fileread_info = regexp(filetext, expr, 'split');
      file_info=regexprep(fileread_info,'Date :','');
      file_info1=regexprep(fileread_info,'verage Reflex Time :','');
      file_info1=regexprep(file_info1,'ms.','');

      avg_ref_time =str2double(file_info1); %convert from cell to array

      date = file_info{1}; %convert from cell to array????

     plot(avg_ref_time,date); <---- cant plot : date is string

Text file data format :

Date : 8/8/2012 10:21:36 Average Reflex Time : 473.7ms.

Answer 1

[Walter Roberson]

datenum(date, 'mm/dd/yyyy hh:mm:ss')   %adjust if dd is before mm