Hi dassets and nztx...a quick line from your favourite Shareholders' Association :-)!
It looks like AIR were granted a waiver by NZ RegCo in relation to the 5 days.
Waivers from Listing Rules 4.17.6(a), 5.1 and 5.2 - NZX, New Zealand’s Exchange
See below:
Waiver from Listing Rule 4.17.6(a)Decision4. Subject to the conditions set out in paragraph 5 below, and on the basis that the information provided by AIR is complete and accurate in all material respects, NZX Regulation Limited (NZ RegCo) grants AIR a waiver from NZX Listing Rule (Rule) 4.17.6(a) to the extent this Rule would otherwise require the notice required under Rule 4.17.6(a) to be be released through MAP no later than five Business Days before the Ex Date for the Rights Issue.
Also, note that the 'record date' for the rights is actually tonight - but with T+2 settlement, in effect, was Friday Apr 1st. With the offer announcement on March 30th, they have essentially had 4 business days.