Does anyone know how long the grace period is between Koru Expiry and renewal? (in terms of how long your membership remains active after expiry, rather than when you will have to pay another joining fee).

I assume there is one because my membership expired 30 November, but I still have "Koru" printed on my boarding pass, and I can still access the lounge.

I ask because I recently ticked over to Gold but that doesn't become effective until 1 Feb next year (so no point renewing Koru), but I still have some flying to do Dec/Jan.

Any insight appreciated.