How to calculate Night Differential

thank you guys, everything went OK.

I'm thinking of jumping certain columns (ex. from C7 jumps to F7) in my worksheet to protect the formula within that cell, could you show me how?

Also in Excel if you hit the enter key its goes down to the next row, is there a ways to make it jump to the next column using the enter key instead of the arrow keys? And lastly, if I reach the last column on my worksheet (ex: K7 column) is it possible to make it jump back to A8.

My apologies, if ask too many questions.