how many days paid holiday in Italy, excluding public holidays?

Answer 1

You get paid 20 days after 1 complete year of work.
This is until the 5th year of work (each working year you'll get paid 20 days).
From the 5th until the 10th year you get paid 22 days x year.
From the 10th year on , you get the maximum = 25 days x year.

However if you change company you'll restart from the beginning.

Answer 2

You would get paid for 20 days after 1 year of work, till the 5th year of work which you get paid 22 days x year till your 10th year of work.
From the 10th year on , you get the maximum of 25 days x year.

Answer 3

Minimum is three weeks (for a full year of work)