In this case, I'm gonna have to strongly urge you to leave it as is.

There are so many repetitions of the same calculation, that if it's all combined into one formula the same calculation ends up being executed many times.

This is very detrimental to performance of your sheet.

I will however tell you how you can do it yourself if you must...

You have the representation of all the formulas there.

Begin with G5

=WORKDAY(H6,J6+N6,$S$6:$S$31)+M6

Take the reference to H6, just copy the formula in H6 (minus the = sign) and paste it into the G5 formula in place of the G5 reference.

so it becomes

=WORKDAY(A6+TIME(B6,0,0),J6+N6,$S$6:$S$31)+M6

You may need to add () around the part you paste in to ensure the order of math operations happen in the correct order.

So you might make that like this instead

=WORKDAY((A6+TIME(B6,0,0)),J6+N6,$S$6:$S$31)+M6

Then do J6

=WORKDAY((A6+TIME(B6,0,0)),**J6**+N6,$S$6:$S$31)+M6

becomes

=WORKDAY(A6+(TIME(B6,0,0)),(INT(I6/$C$3))+N6,$S$6:$S$31)+M6

Just continue repeating that until all references to H6:N6 are gone from G6