AE

AE stood for After Endor and along with BE (Before Endor)was an alternate dating system used by the Yeda Rebel Alliance, Andrew's Empire, Yeda New Republic, and Stan's Empire.

Before the
Since the Yeda Rebel Alliance was formed right after the Battle of Endor, they used that year, 4 ABY as their year 0, as did most of the galaxy until 25 ABY.

However, the Yeda government had another reason: secrecy.

AFTER THE YUUZHAN VONG WAR

When the sabotaged the  late in their invasion, the  planets, including Yeda were isolated from each other. This helped keep the Yeda Rebel Alliance hidden from the rest of the galaxy, thus keeping them from being noticed by the, the , and the Sith Order of Decreto. However, it also kept them from knowing that the Battle of Yavin was now used as the new Year 0 by the rest of the galaxy.

Until the Yeda New Republic restored communications with the rest of the galaxy in 172 ABY, they still used their dating system, which had 172 ABY listed as 168 AE.