Fantastical is an amazing app from Flexibits. Fantastical's uses natural language. Its natural language engine is expressive and intelligent so you can write in your own style. You can type, "Have lunch with Parker on the 25th" and Fantastical will add a 12:00 PM appointment to have lunch with Parker to the 25th of the current month. Even better, Fantastical automatically recognizes the location of your event and can even invite people from Contacts to your event.
This app is not a replacement for your calendar it is more like a digital assistant to help you quickly make appointments and avoid conflicts. It has become my go to when I want to add anything to my Calendar. It works with the Mac Calendar App as well with Google, Yahoo, iCloud, and Exchange.
It can even help you track your tasks. Fantastical supports the same reminders as OS X and iOS, giving you the fastest way to create or update your todo list. Creating a new reminder is as easy as creating a new event: just type in what you need to get done.
If you are like me and like to try an app out before you part ways with your cash to buy it go and get a free trial from the Flexibits website. They also make a iOS version of the app available from the App Store.