I’m about to be a bit nerdy about the galaxy for a moment.
Unlike many other sci-fi universes, the year in the Aquarius Ascendant Universe is NOT equal to a Terrestrial year. It’s several days “off,” which means that the Galactic year in relation to the Terrestrial year tends to drift. Computer software converts dates automatically.
Independent Flight begins on the 18th of First Month, 343 Star Era, and ends on the 8th of Second Month in the same year. This translates to beginning on June 11th, 2529 CE, and ending on June 22nd.
There is no “BSE” on the Star Era calendar. “Year Zero, Star Era” is equal to the year 2178 of the Common Era, when the Treaty of Galactic Alliance was signed, forming the common Star Era calendar. Years before the Star Era began are kept in local time, so a Human referring to an event that happened before the Star Era’s beginning would refer to a Gregorian date.
The galactic year is 9,000 hours in length (this was determined by averaging the length of planetary years), which means that the current year of 343 is 2529/30 CE, and that the galactic year started on May 24th, 2529. It is divided into 12 equal-length months of 750 hours for timekeeping purposes. Those months are subdivided into thirty twenty-five hour days. The months are ordinally numbered, although Humans tend to refer to them by the traditional month names of Earth.
Plenty of religions still observe their own calendars – Anno Mundi, Anno Domini, Anno Hegirae, and multiple other calendars are still in use. Just not for public record keeping. The most common planetary calendar is “After Landing” (“Anno Humanis” on many human-colonized planets), which is almost always calculated to the planetary year, not the standard year.
(Edited to correct dates)