When to leave for Hangzhou airport?

Yes, you may take metro line 1 from Wulin Square to Ding'an Road Station, Exit D, and walk south for about 0.6 mile to the old street. After touring around, you may walk north to the main railway station, and take airport shuttle bus to HGH (about 70 minutes). Usually, it is recommended to reach the airport 2 hours before departure, so you need to leave the old street for HGH at about 10:30. :)

Thanks