User blog comment:SBolton123/Trying to earn a badge/@comment-224939-20170522142045/@comment-1915803-20170522160646

The reason is because Wikia's interface is based on Greenwich Mean Time, Jspy. That's why for us in the Central Time Zone, the day cutoff is between 6 and 7 PM, depending on whether Daylight Saving Time is in effect, since we're five and six hours behind GMT.

According to Wikipedia, South Australia is ahead of GMT by 9:30 or 10:30 depending on DST, so that means your cutoff point is in the mid-morning. To earn the badge, you will want to time your edits accordingly.

Also, yes, any kind of editing counts toward the badge, even commenting.