Differences between adjacent elements of an array (diff(A))

I am trying to either run a script with diff(A), or create a for loop that essentially does the same thing. My outputs for both are the same, but still dont give correct values.

Here is the script

here are the inputs and outputs

[David K.]

Are you showing the theoretical correct outputs? Because they look right to me. Do you wish them to be moved up 1?

Also, to find the difference you can do it without a loop:

diffhours = hourOfRecord(2:end)-hourOfRecord(1:end-1);

[Patrick Jenks]

Thank you!

I thought the magnitiude was off, but I was probably mistaken. I appreciate the help!