It sure would be nice to change the order of the many calendars on the iPhone. Sadly, iOS 6 only lets you show or hide specific calendars with a tap on the calendar in question from within the Calendar app on the iPhone, iPad, or iPod touch.
You can, however, reorder the different calendars on your iPhone, just in a different way. Here’s how.
Drop into a web browser and load up iCloud.com. Log into your iCloud account there, and select Calendar from the icons that appear there. Once you’ve clicked the Calendar icon, you’ll see all the iCloud synced calendars along the left, just as if you were using the OS X version of Calendar. Click, hold, and drag your Calendars into the order you want, and then grab your iOS device.
Launch your Calendar app, and then tap the Calendars icon in the upper right of the screen. At the bottom of that screen, there’s a circular refresh arrow. Tap it and see your calendars re-order themselves. Pretty slick, right?
Note that this will only work with your iCloud-synced calendars. You can re-order your calendars in the OS X version of Calendar as well, but some folks out there have reported that the sync doesn’t always show up correctly on the iOS device. The web-based iCloud solution seems to be the most reliable.