Final answer:
The defendant must respond to a complaint or summons by the date specified in the summons, which is personally served to ensure they are officially notified and can exercise their legal rights. Failure to respond can lead to a default judgment against the defendant.
Step-by-step explanation:
The date by which a defendant must respond to a complaint or summons is provided in the summons itself. The summons is a legal document that is personally served to the defendant to ensure they have been officially notified of the legal action being taken against them and to allow them to prepare a defense or respond to the court. This personal service is essential to uphold due process, ensuring that the defendant is aware of and can exercise their legal rights.
When a defendant is personally served, they are given a specific time frame to submit their response. This can include filing an answer, making a motion, or taking other legal steps as required by the jurisdiction's rules of civil procedure. If the defendant fails to respond within the specified period, they may face a default judgment, which can result in the plaintiff winning the case by default.