To calculate properly the baseline schedule, we have to add the most realistic durations
When you add a task, Ms Project proposes a duration of an estimated day (1?).
We can change the estimated duration to a confirmed duration by writing 10 in the cell of the duration field of the concerned task. There will be no question mark (?).
The days are business days according to the calendar you choose for this project.
We can also show an estimated duration by adding a question mark after the number written in the cell: for example, becomes 
It is also possible to show calendar days, for example for the concrete curing task; by indicating which will stand for 5 elapsed days since curing will occur even on the weekend. You will write the number of day and ed for elapsed day, here will write 5ed.
