Issues with military time showing total hours worked

[Marshallaw]

I am fresh and new to Excel. What I am trying to get the total hours worked (down to a quarter hour) to appear in the smaller box in the corner of each day, but I can not seem to get it to add correctly no mater what I do. Can anyone help me out with a function that will help me out?

Table example:

 

[Marshallaw]

It looks like the issue I was having was that not all the cells were formatted in that way. Now that I did that they all work. Thank you both for the help!