% LogTimeInc should be utilized for time correction.
%   It allows to correct logged time +-1 hour.
%   It was primarily designed for D files created by LOCATOR logger.
%   
%   input.D   - log to be corrected
%   newfile.D - corrected log
%   
% (c) 03/2009 Jan OK1ZHS

clear all
close all

volba = menu('Time +- 1 hour', 'INCREMENTATION','DECREMENTATION'); % incrementation 'I' or decrementation 'D'
switch(volba)
    case(1)
        inkrdekr = 'I';
    case(2)
        inkrdekr = 'D';
end

offset = 1;                         % time offset +-1 hour

if offset>1 error('Incorrect offset value'); end

fid = fopen('input.D');             % file (with incorrect time data) opening
logerr = fread(fid,'uint8=>char')'; % data reading and format conversion

posice = findstr(logerr,':');       % : finding
offmin1 = num2str(offset - 1);       
offmin2 = num2str(24 - offset);       
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%        INCREMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
switch(inkrdekr)
     case('I')                       
for i = 1:length(posice)    
                               ab(i) = str2double(logerr(posice(i)-2:posice(i)-1));
   if ab(i) >= 23
                              stroff = str2double(['0' offmin1]);  % midnight problem solving
     logerr(posice(i)-2:posice(i)-1) = num2str(stroff);
   elseif ab(i)>=0 && ab(i)<9
     logerr(posice(i)-2:posice(i)-1) = ['0' num2str(ab(i) + offset)];
   else 
     logerr(posice(i)-2:posice(i)-1) = num2str(ab(i) + offset);

   end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%        DECREMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    case('D')
        for i = 1:length(posice)    
                               ab(i) = str2double(logerr(posice(i)-2:posice(i)-1))
   if ab(i) <= 0                   
     logerr(posice(i)-2:posice(i)-1) = offmin2;                     % midnight problem solving
   elseif ab(i)>=1 && ab(i)<=10
     logerr(posice(i)-2:posice(i)-1) = ['0' num2str(ab(i) - offset)];
   else
     logerr(posice(i)-2:posice(i)-1) = num2str(ab(i) - offset);

   end
end
end

logerr                             
        
fclose(fid);
fidnew = fopen('newfile.D','w');   % new file creating and opening
fwrite(fidnew,logerr);             % data writting into a new file
fclose(fidnew);