Here is an old article on the Australian "Director buying shares...

Here is an old article on the Australian "Director buying shares are a handy hint". i found the following two paragraphs relevent:

"There are two periods during the year when directors are not allowed to buy shares: the periods before the company's results.

Also, they are not allowed to buy company shares before a major announcement or when they become aware of a significant event."

http://www.theaustralian.com.au/business/wealth/director-buying-shares-are-a-handy-hint/story-e6frgaco-1225759977466