Great Re-Synchronization
this was the name given to the point in galactic history, some thirteen years before the onset of the Clone Wars, when the Republic Measures and Standards Bureau reset the galactic calendar. For more than 5,600 years prior to the change, the galaxy had measured time by the Sidereal Period calendar. The outcome of the Re-Synchronization produced one of the most accurate depictions of galactic time known to the Old Republic.