Jul 12, 2013 · 2 minutes

Calendars haven't grabbed this many headlines since the Mayans' doomsday prediction came, went, and faded back into irrelevance. It seems like we can't go a week without a new calendar-related announcement, whether it's news about another calendar-maker closing a round of funding, the launch of a new calendar app, or an update to existing products. We have officially reached the point at which there is no excuse for ever forgetting another meeting, conference call, or event.

First came the news that Sunrise, a calendar maker founded by a former Foursquare designers, had raised $2.2 million in seed funding. Then Any.do announced its own calendar app, Cal, which officially launched yesterday. Then Tempo AI announced that it had raised $10 million to continue building its solution, the Tempo Smart Calendar. And then, finally, UpTo announced yesterday that it had updated its product to make it an especially social calendar.

And you thought photo-sharing applications were popular.

By now it would be all too easy to dismiss the category and purchase an honest-to-goodness desk calendar or daybook. I'm not sure how many products need to be released before people start to experience decision fatigue -- a state in which the brain ends up making no choice simply because there are too many options -- but we've gotta be nearing that number. How many ways are there to change calendars?

The answer, believe it or not, is "a lot." While each of the applications listed above share certain similarities, they also have a wide variety of features and differing goals. Sunrise wants to help its users save a few minutes out of their day. Tempo AI wants to use the data gleaned from the Tempo Smart Calendar to build an "assistive layer" into other services and applications. UpTo wants to help users keep track of their families, friends, and interests, such as sports, concerts, or media-sponsored events. Other companies simply want to make it a little easier for users to manage their calendars.

Calendar apps have become the new sandbox in which companies can experiment with interaction design, social features, and plentiful data. They also allow companies to peer into their users' future, as UpTo CEO Greg Schwartz told me. There are plenty of ways for companies to gather data about their users' past. An increasing number of utilities, from ambient location tools to check-in applications, allow companies to gather information about the present. Calendars are currently the best way to look into a user's future.

I've argued before that an over-abundance of apps isn't the same as app burnout, which might prevent consumers from trying new applications and services. The same argument might be applied to calendar apps; though the market is becoming increasingly saturated, the extent to which these applications are able to differentiate themselves allows these companies to release new products and, potentially, find a receptive market for them.

I'm still considering that desk calendar, though.