From ASIC:
Time for giving notice
RG 159.264 A person must give a substantial holding notice within
2 business days of becoming or ceasing to be a substantial holder or
moving at least 1% (or by 9.30 am next business day during a
takeover bid), whether or not they have completed a larger investment
move or unwound their investment position within that time:
s671B(6)(a).