sidereal time

But one puzzling signal showed up most days at the same sidereal time.

One of its functions shows sidereal time, which is based on the amount of time it takes the Earth to make two consecutive transitions of a meridian by a fixed start.

He described it as having everything needed “for your package tour to Mars,” including mean-solar and sidereal time, age and phase of the moon and equation of time indicators.

Says Kern, “The combination of solar time and sidereal time in the same watch was certainly not the idea initially, but it is a clear indication that unusual things take time.”

When time is calculated by the stars it is called sidereal time; when by the sun, solar, or apparent time.