The first thing you'll notice when you install Any.do is that you can sync it with any other calendar installed on your device, such as Google Calendar or Exchange. If you want, you can also sync dates from your Facebook account or your address book.
When you create reminders, there are lots of options at your disposal. Choose the name of each reminder and when you want the app to remind you of it (between two days and ten minutes before the actual event). You can even set several reminders, for instance one for the day before and another for just a moment prior.
Any.do is a comprehensive calendar and agenda that includes lots of features aimed at improving your productivity.