Create a Custom Calculator in Google Sheets

We operate a food store where we have an arranged amount of customers visiting us every day. We are looking for someone to be able to design a custom google sheet that would allow us to enter the date, opening and closing times for the shop, the number of people booked in to visit us for the day which would then present it in a way that divides the number of customers by the hours the shop is open.

Then we would want that presented in a table with the hourly amount of people.

Further, we would like to be able to then edit those numbers throughout the day and depending on the number of people being served at the store each hour, we would be presented with a number based on the average hourly numbers showing how many customers may be left over at the end of the day, from the original number predicted at the start of the day.

An example would be ( obviously the design of the sheet would have details in different cells )

- Date ; 00.00.18
- Opening Time ; 0800 hours
- Closing Time ; 1800 hours
- Total Hours Open ; 10 hours
- Total No People ; 300

= 30 People an hour

0800 hours - 30/ph
0900 hours - 30/ph
1000 hours - 30/ph
1100 hours - 30/ph
1200 hours - 30/ph
1300 hours - 30/ph
1400 hours - 30/ph
1500 hours - 30/ph
1600 hours - 30/ph
1700 hours - 30/ph
1800 hours - 30/ph

Left Over : 0

But if during the morning, the customers go through the store more slowly or quickly than predicted, then the 'Left over' figure at the end would change to show the number of people who may be left over.

So for example ;

0800 hours - 30/ph
0900 hours - 27/ph
1000 hours - 41/ph
1100 hours - 25/ph
1200 hours - 30/ph
1300 hours - 30/ph
1400 hours - 30/ph
1500 hours - 30/ph
1600 hours - 30/ph
1700 hours - 30/ph
1800 hours - 30/ph

Left Over : 3