Theron's Hourglass

You, create a translucent, spherical demiplane with a radius of up to 50 feet centered on a point you choose within range. Time within this area passed at an accelerated rate of 24 hours for every hour outside. Anyone inside the sphere sees the outside world as almost entirely motionless. Those outside see the interior as a blurred chaos of motion. When this spell is cast, a short high-pitched whine can be heard out to 1 mile.

Creatures and objects can pass into and out of the demiplane, but no spell or magical effect created on one side of it can affect the other.

You can end the spell early by using an action to dismiss it.