How do I replace data in an array in a specific order?

I'm attempting to write a chunk of code that takes a 5 x 2 array of doubles, locate specific times in the first column of data, and replaces them with updated values. The code I am working with is as follows;

clear all;
clc;

% 5 x 2 array of doubles
% column 1 contains state times in UTC
% Column 2 is time tagged data
UTC_Data = [86100 1; 86200 2; 500 3; 86400 4; 1000 5];

% Assign state times
State_Times = UTC_Data(:,1);

% Assign an initial scenario time in UTC
I_Time = 86000;

% Calculate the time difference between 86400 and I_time
T_Diff = 86400 - I_Time;

ind1 = find(State_Times > I_Time);
if size (ind1) > 0
    UTC_Non_Rollover = State_Times(ind1) - I_Time;
else
    UTC_Non_Rollover = [ ];
end

ind2 = find(State_Times < I_Time);
if size (ind2) > 0
    UTC_Rollover = State_Times(ind2) + T_Diff;
else
    UTC_Rollover = [ ];
end

The resulting 5 x 2 array ,B, should look like this:

100  1
200  2
900  3
400  4
1400  5

Is there a way to get the applicable times in their proper order in B?

Thank you.

Answer 1

[Stephen23]

Method One: rem:

UTC_Data = [86100 1; 86200 2; 500 3; 86400 4; 1000 5];
I_Time = 86000;
T_Diff = 86400 - I_Time;
%
C = UTC_Data;
C(:,1) = rem(C(:,1),I_Time) + T_Diff*(C(:,1)<I_Time)

Creates the output C:

C =
    100      1
    200      2
    900      3
    400      4
   1400      5

Method Two: Logical Indexing:

B = UTC_Data;
idn = UTC_Data(:,1)>I_Time;
B(idn,1) = B(idn,1) - I_Time;
idr = UTC_Data(:,1)<I_Time;
B(idr,1) = B(idr,1) + T_Diff

creates the variable B

B =
    100      1
    200      2
    900      3
    400      4
   1400      5

[Brad]

Method 2 runs like a champ! Thanks Stephen.