A hub is a short path through calculators that answer one decision. The math is not combined. You open the next page when the previous result is the input you actually have.
Five calculators, in the order you would actually use them. Each one keeps its own assumption. This page does not blend them into a single forecast.
Tip first if the bill is already one number. Use the split when tax and the tip base are separate lines.
The calendar difference and the working-day count are different questions. They stay on different pages so the headline is not doing two jobs.