User blog comment:Rhiabloom12/Gardenia's Location and Alfea's School Year/@comment-29197449-20170403170114

I think I'd have to agree with Alfea's school year being from October to August. Thanks to the worldwide zoom in Season 4 as the Winx were traveling to Earth, we can see that Gardenia is based somewhere along the southwestern coast of the US; specifically in the California area, so there's no way it'd be in the Southern Hemisphere.

There's also the fact that the Magic Dimension may follow a calendar that would seem odd to what we follow (different realms orbiting different stars, etc).