Subtract 8 hours from time

I have google table with time columns. These columns are Time format, and i use formula to calculate worked hours - 8 hours needed to know whether i worked over 8 hours or less.

Pretty simple formula.

=E*-TIME(8;0;0)

But when i work less than 8 hours, it shows 23 hours instead of -7 hours for example. I want my top F1 cell to count sum of all over/less worked hours, and the rest F contain E*-TIME(8;0;0) values.