Number of days allocated for a task miscalculated

I’ve put a task starting on 20-05-29 for a 28 days but it shows that it’s supposed to on end on 20-07-07.
But 28 days after may 29th should be june 26th?

How i can fix this problem?
Thank you!

I don’t know how did you set up weekend days, but if you just used the default calendar, then Saturday and Sunday are non-working weekend days. 28 working days starting from May 29 end on July 7.

Thank you very much!