Yom ha-din ( the last day of creation, the seventh day )
The Last Day of Creation, the seventh day, will last 1000 years, the age of Mashiach. We're currently living in the sixth day of creation, hebrew year 5781, 6th millennia since creation of this particular world. How many times has this world been created and destroyed, only G-d knows. At the end of the messianic Age, G-d will send us all to Olam Ha Ba, the world to come. The good and the wicked cannot exist together in harmony for eternities in the world to come. Hence the judgment will be immediate after the resurrection of the previously dead at the end of Yom Ha Din.