The Hachioji Hanabi Taikai is being held one week earlier than usual this year due to ground maintenance. At 3,000 or so rockets, it might not be up there with the biggest of Tokyo’s many firework events, but you can expect smaller crowds (relatively speaking) and a better view.
Event details are taken from official sources whenever possible. It is always prudent to check the official event website before attending to make sure that there have not been any changes. If you know of an error in the calendar, then please let me know through the contact form.