Quote Originally Posted by Sky Shadow View Post
It's actually about a year. In Animated and Beast Wars a stellar cycle is approximately an Earth year, in IDW comics it's more like 2/3 of a year.
It appears that by and large the Transformers (as with humans) use stellar indicators to measure time and, creative license aside, this means that when talking time, a point of origin should also be required (we can maybe asume this point-of-origin is transmited sub-vocally at the same time as they vocalise the time - This would account for the vagaries of duration applied to the 'cycle' terms) - Afterall a day/Orbital-cycle on Titan is a different length to a day/orbital-cycle on Mars, just as Midday, Perth isn't the same as Midday, New York.

A stellar/solar cycle is a localised time unit referring to the time it takes for the planet the Transformer is currently on to orbit its star. This means it's different on each planet they may be on. It is similar with the Orbital-Cycles/Solar-Cycles, Cycles, Mega-Cycles, Nano-cycles - they're all planet specific.

The only purely Cybertronian measurements of time are:
Breems (8.35 minutes - This is a planetary time measurement);
Orns (1.15972222 days - This is an planetary time measurement);
Decivorn (8.35 years - This is a planetary time measurement [Deci being /10]);
Vorns (83.5 years - This is a planetary time measurement);
Decavorn (835 years - This is a planetary time measurement [Deca being *10]);

Groons (1.656746032 weeks - This is a lunar time measurement - The Magnificent Six - Megadeath says he'll trigger the bombs in 2 Groons time, but he leaves the Autobots imprisonned until releasing them 2 hours before firing them.);
Joors (41.75 minutes - This is a lunar time measurement);

Mara (5.79861111 days - This is a lunar time measurement - Trimara [Three-moons - Mara is a Slavic lunar godess] = 17.3958333 days);
Quartex (1.524102823 months - This is a solar time measurement)

I would asume that the planetary measures were developed while Cybertron was stil in the orbit of Alpha Centauri - 1 planetary rotation = 1 day/orn. When Cybertron was blown free of its orbit (taking its 2 moons with it) it was likely that the lunar interpolations either came into existance or became more popular. The solar time measurement indicates a portion of the length of time it takes for the planet to orbit its sun (like seasons).