Looking at the on-time performance of VX 357 BOS-SFO, it is pretty awful.

Normally it departs BOS at 715p EDT, and arrive in SFO at around 1015p PDT.

Doing a quick check, looks like they are running really late on multiple occasions:
June 4: estimated to arrive at 1:20 am June 5
May 31: 1:30 am June 1
May 30: 12:10 am May 31
May 29: 12:07 am May 30
May 28: 11:50 pm
May 26: 12:50 am May 27
May 25: 2:33 am May 26

This almost feels like a westbound red-eye flight for people that are used to Eastern Time Zone.