Duplicate Time

In combat, This spell uses your entire turn, action, bonus action, reaction, free action, and movement. If used outside of combat, you reverse the last six seconds. 

When this spell is used in combat, the round starting after your previous turn is rewinded, and only you notice the change. If used outside of combat, you reverse the last six seconds, including damage taken from everyone in the room. Every spell and attack made by other characters is the same as was made, but ranged and melee attacks by other creatures are made with disadvantage, and any saving throw you had to make you instead make with advantage, unless it is a CON saving throw. After casting this spell, and after the round is redone with adjusted attacks and saving throws, you take another turn, as if you hadn't used your turn to use the spell. You still lose the spell slot you used to cast the spell. 

The spell is cast on the entire world, but everyone else in the world does exactly the same thing they did before the spell was cast, so there is virtually no effect. Only Chronurgy wizards and powerful beings such as gods notice the spell being cast.