One is in Cannon Falls, Minn at 12:05 central time (1:05 pm ET or 10:05 am Pacific). The other is in Decorah, Iowa at 5:15 pm central time (6:15 pm ET or 3 pm Pacific)
The town halls will be live streamed here.
Obama will be on a three-day bus tour that runs Aug. 15-17. See the full three day schedule here.