Ann: Daily share buy-back notice - Appendix 3E, page-4

Correction: the buy back was approved at the meeting held on 17 Dec.

Diectors and management are prohibited from trading in shares during the blackout period commencing 15 Dec until after release of the half year results:
https://www.cardno.com/media/3177/cardno-securities-trading-policy.pdf

It would be reasonable to consider this restriction to also applied to the directors initiating a buy back during that period.

Thus they could not have started the buy back until very recently.