By default when we create a new project in Microsoft Project it use 5 day work week. How about we want to use 6 day work week.

I will show you how to do it.

We have a simple project using default 5 days work week.

We can see a task with 10 days duration start on 16-Sep and finish on 29-Sep.

Now we will change Project calendar from 5 days work-week to 6 days work-week.

Go to menu Project -> Change Working Time

Click on Work Weeks tab and Detail button.

Click on Saturday, Select “Set days to these specific working times”, Enter the working time.

Click OK.

Now we can see Saturday is working day.

We can add National Holiday by click on Exceptions tab. Enter holiday name, Start, Finish date of holiday.

Now from 5-Feb-17 until 11-Feb-17 is non-working day.

After finish everything we click OK. Now our project use 6 days work-week. And we can see the task now finish earlier on 27-Sep.