Change clock to 24-hour time

If you're used to getting up at O'dark-thirty and go to bed sometime around 2100, you might want to switch your clock over to 24-hour time.

Also commonly called "military time," that's where the afternoon shift switches to 1200 to 2400, taking care of those pesky a.m./p.m. concerns. And switching your phone is easy. Just go to Settings>Date & Time and check "Use 24-hour format."