Top calendar apps for iOS, Android, Windows

There's a software category, an important one, where there's no standard design or set of features: calendar. Each one seems to have evolved on its own Galapagos island. 

Take the new calendar app in Windows 8. So much of Windows 8's touchscreen mode is modern, updated and fresh — colour, gestures, typography — that you'd expect an equally modernized calendar app at its heart. Wow, would you be wrong. 

You can't drag vertically through the Day-view column to create an appointment. You can't drag an appointment to reschedule it. You can't record an autorepeating appointment like "Monday, Wednesday, Friday" or "first Tuesday of the month." 

If you could mix and match the best of all the motley calendar apps, here's what you might come up with. 

Give us an alternative to tabbing from Start Time to End Time and typing numbers into a New Event box. Let us drag to indicate a meeting's length. Or give us speech — intelligent speech, like Siri on the iPhone. ( Google, Apple's Calendar for the Mac, BusyCal and, in particular, the iPhone app Fantastical can all do this.) Here again, you're not fiddling with a dialogue box to enter a new event. 

Microsoft's greatest calendaring effort remains Outlook, the e-mail program that comes with some versions of Microsoft Office. Outlook has its detractors, but one thing it got right is integration with your e-mail and address book. Some calendars, like Apple's Calendar and BusyCal, offer a "heat map." It's a year view in which deepening colours in the yellow-orange-red scale indicate increasingly busy times of your life. 

Why are we limited to words when our gadgets are digital? We should be able to put pictures, voice recordings, videos and documents on our calendars, too. 

Any decent calendar program lets you put appointments into categories like Home, Work and Social. The really good ones, like BusyCal and VueMinder Lite (free for Windows), also let you put those categories into groups. 

What else should be there? Reminders — via text message , e-mail or pop-up bubble. Invitations to meetings and events, and RSVP's. Duplicate removal. Smart timezone adjustment. 

Finally, it goes without saying that all modern calendars should sync. To our other computers. To our phones. To the Web. We should never, ever have to enter an appointment on more than one machine. 

The world's software makers have made great strides helping us manage our money, our phone numbers and our files. Now how about equal time for time?