Cushrath's Time Dilation

You invoke a 1 square mile demi-plane that exists for 1 hour, and at the conclusion collapses.

This plane of existence is a mirror of the current plane and represents a clone of one of infinite multiverse futures. When you cast this spell, all creatures within 60 feet of the caster make a Wisdom saving throw to detect their inclusion in this alternate timeline.

At the collapse of this demi-plane, the caster, and all creatures with a successful saving throw recall memories of the events that unfold within the demi-plane, but any and all physical or magical effects do not persist. Upon returning to the previous plane of existence, no time has elapsed, and for creatures with a failed saving throw there is no perception of this alternative event with the exception of direct observation of the casting of this spell.