I looked into award travel on UA for June 20/returning July 11. Saver award economy is available for only one flight on June 20; leave BOS 5:58 PM, arrive LAX 10:45 PM, with a connection in Cleveland. Return is available on July 11 leaving LAX 10:40 AM and arriving in BOS 10:25 PM, with a connection in Newark. Several return options are also available July 10.