Non-Serializable Values Like Date Objects Should Not Be Stored Directly in Redux State

Redux Toolkit will throw a synchronous runtime error and refuse to update the store whenever a non-serializable value like a Date object is present in state.

Storing a Date object breaks time-travel debugging, state persistence, and action logging, which depend on state being serializable; the recommended fix is storing an ISO string or Unix timestamp and converting to a Date object only at the point of use.

Date objects are automatically serialized to strings by Redux Toolkit's default middleware, so there is no practical issue with this pattern.

This only causes problems in development mode with Redux DevTools installed, and has zero effect in a production build's runtime behavior.