How can I get Days Inn international hotel from Xian airport? our flight arrive around 10pm.

Do you refer to Days Inn City Centre in that city on North Street?
If so, you can take the airport shuttle bus line 1 to reach its terminal at Bell Tower and then take a taxi to reach your hotel directly. Or you can walk along the North Street to reach your hotel easily. The taxi fare is around 10RMB.

Yes, the hotel is like you said.
Thank you very much.