</Tabs>

The`error` param optionally accepts a function. An error customization function is known as an**error map** in Zod terminology. The error map willcan at parse time if a valiation error occurs.

The`error` param optionally accepts a function. An error customization function is known as an**error map** in Zod terminology. The error map willrun at parse time if a valiation error occurs.

z.string({error: ()=>`[${Date.now()}]: Validation failure.` });