Good app one problem – Any.do: To do list & Planner Review

I love this app. I use it to remember tasks and chores I need to do around the house but I have one problem. Every time I try to add a event to my calendar I fill out the information and when I finish I press “add” and then it tells me it can’t add the event because I haven’t set up my calendar. I have been trying to figure out how to set up my calendar but every time I try it does not work. Can someone please tell me how to set up my calendar. But other than that it’s a amazing app.
Review by vivi's fun land on Any.do: To do list & Planner.