Finding the night differential of two time

     
  

I have this two variable:

  

$time_in = 21:00:00;  $time_out = 05:00:00;  

  

I just want to know how I should compute the number of hours of night   differential:

  

Night differential time are:


22:00:00 - 06:00:00


  

I just want to know if you could suggest anything that can help me for   this if their is a function for this or should I use manually compute   it?

  
  
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answer1
  
  

I can not understand properly what you really want to do.


I got this conclusion as I understood


If you use 24-hour time format then specify the date with time