Time apportioning EPS

I am having trouble understanding when to apply which fractions when calculating the weighted average number of equity shares for EPS. My understanding is that when there is a share issue, each prior total number of shares should be “time apportioned” in order to be weighted (e.g. 3/12 for the outstanding number of the first three months of the year before an issue is made in the fourth month and so on). But I have come across some questions on the BPP revision text book that haven’t time apportioned the issues. Please could I get some help on this? See the below example:

Company had share capital of $7.5 million in 50 cents equity shares at 1st Oct 20×6. On 1st Jan 20×7 made an issue of 4 million shares at full market price immediately followed by a 1 for 3 bonus issue.
The financial statements at 30 Sep 20×7 showed profit of $12 mil.
What is the EPS for the year?

Answer:

B/f (7,500/.5) 15,000.00
Full Market Price issue ( 4,000 X 9/12) 3,000.00
Bonus Issue (18,000/3) 6,000.00
Total 24,000.00

EPS 12/24 $.50