"Of the events that have transpired over the last year, there are many rumors and far fewer facts. Those rumors could all be dispelled by having an exact chronology of events created, and perhaps, in another generation or two, such a chronology could be made public. While we were a covert force fighting against the Empire, there was no questioning the need for stealth and secrecy. It was what kept us alive and allowed us to fight on against the Empire. Because of this secrecy we have defeated them in battle after battle."
―New Republic Chief of State Mon Mothma, following Ysanne Isard's final flight from Coruscant[src]
↑The New Essential Chronology states that the Ruusan Reformation occurred in 1000 BBY, which is the zero point of the calendar based on the Ruusan Reformation, so the difference between the calendar based on the Battle of Yavin and the Ruusan Reformation's year-notation system is 1,000 years. This date is derived using simple math based upon other confirmed dates.
↑The Essential Atlas places the Battle of Yavin, the zero point in the Galactic Standard Calendar, in 35:3 under the Great ReSynchronization dating system. The Essential Atlas also places the Battle of Selaggis on 43:2:28 and the Battle of Dathomir on 43:3:21. The Essential Guide to Warfare and The Essential Atlas both place the Battle of Dathomir in 8 ABY. The Essential Guide to Warfare also places the Battle of Selaggis in 7 ABY, confirming the placement of the division between each Galactic Standard Calendar year as the third month in the Great ReSynchronization year. Thus, there is a two-month gap between the two dating systems, and the first two months of a GrS year are the last two of the preceding Galactic Standard Calendar year. The Great ReSynchronization was instituted in 35 BBY, so there is a total difference of 35 years and 2 months between the two systems. This article's date is therefore derived from simple math based on this reference explanation.