Standard year/Legends

A year was a measurement of time on the Galactic Standard Calendar, consisting of 368 standard days, with twelve months of at least 30 days.

The length of a planetary year was determined by the orbital radius and speed of the planet. Satellite planets - moons orbiting a gas giant - were almost always tide-locked to the gas giant they orbited, and may have days several dozen hours long (as long as it takes the satellite to orbit the gas giant). The local year of a satellite depends on the orbit of the gas giant and may be several Standard Years long.

Behind the scenes
Star Wars: The Roleplaying Game originally established a year that contained ten standard months (of seven standard weeks consisting of five days) plus three Fete Weeks and three more holidays, though this was overridden in favor of a 12-month dating system in later sources.