Chronectasis

Casting this spell artificially lengthens time in a small area, disrupting the natural flow. Choose a point within range; a translucent sphere with a radius of 10 feet appears at the point you choose. Time passes much slower in this area; while inside the sphere creatures suffer -2 to their AC, have halved movement speed, and have disadvantage on any rolls relating to space outside the sphere. 

Exiting the sphere immediately halts these effects.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the radius of the effect increases by 5 feet for each slot level over 3rd.