Perhaps no new Calendar feature will be more welcome than the overdue ability to swipe between days. To move from day to day in the old version of Calendar, iOS device users had to rely on the tiny left and right navigation arrows. With iOS 5, simply swiping across the screen in either direction takes you to a brand-new day.
Similarly welcome is a new landscape mode on the iPhone. Rotate your iPhone to the wider mode from nearly any screen in the Calendar app, and you'll see an endless scrolling horizontal calendar view. (If you enter landscape while adding a new event, you simply get the widescreen keyboard but remain on the New Event screen.)
Speaking of creating events, iOS 5 ushers in a host of improvements to that process. You can tap and hold on your calendar to create a new event set for the time that you tapped. If you're in Month view, tap and hold on a specific day to do the same thing. Also new is the ability to tap and drag events to move them to new times. And when you tap on events, you can use the tiny dots that appear to adjust their start and end times, too.
When you're typing in the details of a new event, the updated Calendar app makes things easier than before. The Title field is pre-selected, meaning that the virtual keyboard is already present, instead of waiting for you to make your first tap. The Notes field used to make you navigate to a separate screen; in iOS 5, it's now fully embedded in the main event-creation screen instead.
At long last, you can finally save customized default alert times in Calendar. Head over to the Settings app, and under Mail, Contacts, Calendars, you can set separate default alert times for birthdays, events, and all-day events. (The specific options are limited--you can't set a default alert about an all-day event for 9pm the night before, for example--and there's no way to schedule more than one alert for the same event.)
Other Calendar improvements support Apple's stated goal of detethering your iOS device from your Mac. You can now add, edit, and delete calendars straight from your iPad or iPhone--no computer required. Another new option allows you to change the pastel colors of your calendar(s); you can't pick colors willy-nilly, but you may choose among seven lovely hues.
Calendar mostly feels the same as it did in previous incarnations--but as if it's just received an affectionate tune-up. The app is easier to use, particularly for adding new tasks, and it gains just enough to make using it simpler and more efficient.