Today is a blue moon. I was lucky enough to see it earlier this evening, before the clouds swept in and it started raining.
No, it's not really blue. It means that it's the second full moon in a calendar month. The previous full moon was on June 1.
I've just checked the Melbourne planetarium site, and it says that the full moon is at 23:50 (Aus EST) today, so it only just scrapes in! I've never before considered that the full moon has a specific time, but it is no doubt for similar reasons that the solstice occurs at a specific time.