Galactic Standard Time (GST) is the most popular time system in the Frontier. It was established by the Pan-Galactic Corporation in order to create a standardized system for record-keeping and coordination across multiple planets and star systems in the Frontier. 
The GST system uses hours, minutes and seconds:
A second is defined as the length of time needed for a beam of light to travel 300,000 kilometers through a vacuum.
A minute is 60 seconds long.
An hour is 60 minutes long.
One year in Galactic Standard Time is 8,000 hours long.
A standard year is divided into 400 20-hour days. Each day is divided into a 10-hour work period and a 10-hour rest period. These standardized days and years are used mainly for record-keeping.
Though not formally defined by GST, by convention a week consists of five days of work and three days off for a total of eight days.
GST does not include months as such, but some users keep note of quarters (corresponding to the quarters of the financial year.
It should be noted that there are no "leap" years, hours, seconds, or fractional seconds in GST; it is constant so that other systems may use it for calibration purposes. These other systems add "leap" measurements to keep pace with both GST and their local astronomical calendar.
The central clock in the Frontier is maintained at Pan-Galactic Corporation's headquarters in Port Loren, Gran Quivera, Prenglar. This highly accurate atomic clock marks the passing hours, days and years, communicating via dedicated subspace radio link to each system within range. Most Frontier residents refer to this as "GST Time", but the military and Star Law call it "Zero Time", much like Zulu Time on Earth.
Each Frontier and Rim world synchronizes its central clock by sending a subspace radio signal to the central clock in Gran Quivera. The signal initiates a series of "pings" on each end that precisely measure the delay of the response signal, accounting for each world's relativistic movement through space in relation to Gran Quivera.
Similar networks exist among nearby worlds, with computers synchronizing both worlds with the central computer at Gran Quivera, enabling the entire Frontier (and Rim) to have a highly reliable Zero Time standard.
In the real world, a beam of light crosses 299,792.458 km in one second (known as one Light Second) in a vacuum, which is very close to the GST definition of one second, but not exact; this means that either:
- The GST Second does not correspond exactly to a Real World Light Second, or:
- A Star Frontiers meter (measure of distance) does not correspond exactly to a real world meter. (This is the likelier of the two: real-world meters are based on the diameter of Earth, meaning that another standard was used to determine the length of a SF meter.)
The difference is negligible for daily use, but one area that is affected is the year; the 400-day GST year (8,000 GST Hours) is markedly shorter than the 365-day (8,765.81 hours) Real-World equivalent (by over a month, which is approximately 725 hours long).
This is an important consideration for characters; a character who is 20 GST years old would be just over 18 using Earth-standard years.
- ↑ Star Frontiers Alpha Dawn Expanded Rulebook pp.52
- ↑ Dragon Magazine "The Mighty Mega-Corporations"
- ↑ Besides Galactic Standard Time, many planets have their own local time system. These local systems use GST seconds, minutes, and hours, but the length of the day and year varies from planet to planet. The length of a local day is the time it takes for the planet to rotate through one complete day/night cycle. A local day is usually divided into equal periods of light and darkness, although these can vary if the planet's axis is tilted in relation to its orbit. A local year is the length of time the planet takes to make one complete revolution around its star.
- ↑ Alpha Dawn Expanded Rulebook pp.55