Sign up here to get Beyond the Back Page delivered to your inbox each weekday morning.

The Islanders and their fans have waited for more than three largely painful decades — plus another 13 games over 35 days to open this season — for the grand-opening moment that finally is upon them on Saturday night.

The housing market has been booming on Long Island for months now, but the Islanders’ state-of-the-art, $1.1 billion new home at Belmont Park has been years in the making. It’s something many of us who’ve followed the team professionally or personally over that grueling span — and have taken an “I’ll believe it when I see it” stance — now can officially believe in its existence.

It’s here. They did it. And it’s amazing.