Question: Why when I put 2 days the calendar does not correspond. If the task lasts 2 days, why does the calendar show 1 day? Thank you 

Answer: This is based on your calendars created and project properties created. Remember it goes by shifts. If your duration is 8 hours. A 24hr calendar will show as 1 day. That is two 8hr shifts.  You would want the calendar to be 24 hours then change your duration in Project properties to 24 hrs 7 days a week 30 days a month.