This question resolves as the date a Starship is first launched as a second stage (such as stacked on top of the Super Heavy booster) and reaches an altitude of at least 100 kilometers intact. There need not be a human on board for this question to resolve.

A Starship is defined as a SpaceX vehicle meeting the following criteria (based on the criteria used here):

Not an existing member of the Falcon family (Falcon 9/Heavy) or a Falcon derivative
Intended to be fully reusable, with every stage returned to Earth (smaller portions such as fairings may be expended)
The vehicle must have a stated payload capacity to LEO of at least 20,000 kg (of pure payload, e.g. the Space Shuttle Orbiter would not count as payload mass). This is very conservative, so Starship would qualify even if it were greatly scaled down from today. There is no payload requirement for the flight itself.
The vehicle should be representative of a vehicle intended to carry a payload to Mars at some point, according to public statements of SpaceX or its representatives.

If this does not occur before January 1, 2026, then this resolves as "> December 31, 2025"