MATLAB: Time difference(milliseconds) at midnight error!

Question

Hello,

I am calcualting the time diffrence beetwen a set of values (duration) , it`s working but calculating t.d. at midnight gives me wrong answer:

for i=6:100
     disp(milliseconds(td(i) - td(i-5)) - 20000);
end    

I have the -20000 bc I always have a 20 seconds delay , I am only interested in the ms without the 20 s

example of my td :

....
'23:59:55'
'23:59:56'
'23:59:56'
'00:00:16'
'00:00:16'
'00:00:17'
'00:00:17'
'00:00:17'
'00:00:37'
'00:00:37'
....

and the output is :

748
748
748
-86399252
-86399236
-86399252
-86399252
-86399252
748
732

until midnight all the values are correct , I calculated them myself,.

how can I solve the problem for the midnight time diff?

*I am using matlab R2017b

Answer 1

ntd = td(:)+cumsum([0;diff(td(:))<0])*days(1);

Now apply your code to ntd .