Forum:KB:Establishing the Rebel base on Yavin 4

The New Essential Chronology doesn't seem to provide a date for the establishment of the Rebel base on Yavin 4. Our article on the moon claims the base was put there in 1 BBY, but there is no source cited for that date. Does anyone know of a source that definitively states when the Alliance moved operations to the moon? ~ Savage  13:28, January 15, 2013 (UTC)