This creates a separate quest with a new ID and fresh progress. Pick its kids and a new end date. The original quest and its earned rewards stay in your history.
Repeatable quests earn one reward unit for each approved completion. Rewards accumulate until the end date below, then your child claims the total and you mark it as given. Daily resets at midnight Singapore time; weekly resets on Monday. Choose Each for repeatable quests. Reward and difficulty stay fixed once a child starts.