for a 5 1/2 trip to Xi'an what is the best attractions and timetable to visit

Hi, the Terracotta Warriors Museum, Huaqing Hot Spring Pool, Mt. Hua, Tang Paradise, City Wall and Big Wild Goose Pagoda are all attractive scenic spots, which should not be missed.

As for your 5.5day trip, I suggest you refer to the website below, which may help you out:
https://www.travelchinaguide.com/package/xian.htm