There are quite a few threads on dividends/ex-dividend on ASF.
https://www.aussiestockforums.com/forums/search.php?searchid=1248811
Click this link and a multitude of options will appear that should answer this question and any others that you may have regarding this topic.
Just a friendly suggestion, try typing ex dividends into the search box in the top right hand corner, rather than start a new thread. Invariably your question will have been answered before and will save you time and moderators the trouble of having to merge threads.
This is the premier thread on ASF for new members to ask questions.
https://www.aussiestockforums.com/forums/search.php?searchid=1248814