I am not so focused on what exact date the target of starting the plant is. The real news of the pilot plant moving from commissioning to production (startup) will have everyone forgetting the date was actually a day, week, or month ago. Yes we as investors are disappointed of the missed date, but doesn't mean that I or anyone else should take our eye off the ball.
For those who sold off their holdings in HPQ because of nothing happening March 31 you are either smart for bailing, or stupid for not hanging on. The answer will soon be known, my bet is the pilot plant will be starting in the near future and the price increasing.