Get the number of days between two dates in Oracle, inclusive of the dates

Question

I want to get total number of days between two provided dates. I\'ve tried the below query but didn\'t get the exact different; the last date is not being included.

Answer 1

In Oracle substracting two dates returns the number of days between two dates.
A minus operator works in the same way as for numbers:

20 - 20 = 0   ===>      2013-05-20  -  2013-05-20 = 0
25 - 20 = 5   ===>      2013-05-25  -  2013-05-20 = 5

If you want to include last number or last date, you need to add 1:

20 - 20 + 1 = 1   ===>      2013-05-20  -  2013-05-20  + 1 = 1
25 - 20 + 1 = 6   ===>      2013-05-25  -  2013-05-20  + 1 = 6