From
AIP SUP H02/23
An SFIS will be provided to all aircraft within the YBNA MBA between 2200 and 0800 UTC (1 HR earlier during AEDT), or as notified by NOTAM.
B1132/23 REVIEW B1125/23 BALLINA SURVEILLANCE FLIGHT INFORMATION SERVICE (SFIS) NOT AVBL
DUE OPR RESTRICTIONS. BALLINA BROADCAST AREA REMAINS CLASS G AS PER
AIP - OUTSIDE SURVEILLANCE FLIGHT INFORMATION SERVICE (SFIS) HR
COMMON TRAFFIC ADVISORY FREQ 124.2
SFC TO 8500FT AMSL
FROM 08 030000 TO 08 060620
DAILY 0000/0100 0300/0400 0600/0620
Closures throughout the day seems to be pretty standard.