In the morning thirty students from the first year gathered in the open grounds, where once the entrance exam took place. They assembled here because today is the day that the portal to the secret realm opens.
They are all waiting for the students from other academies to appear at the moment.
The portal opens in an hour and after another hour, the portal closes its ENTER function and only the EXIT function remains. As long as the students can enter the realm within the hour after it is open, they can enjoy the benefits of the realm.
No one is stupid enough though. They wouldn't want to lose an hour of their time in the secret realm. No matter when you enter, everyone's exit time is the same.