How to save data on one view controller & retrieve it from another view controller

I am trying to make an app where when you click a button a UILabel outputs data & i want to be able to save the data onto another view controller where the data is sorted by date & time & it gets saved onto different view controllers. (Data from monday gets saved in monday, data from tuesday gets saved in tuesday) Each day of the week has a different view contoller. Can someone please help me i am using Xcode6 objective C & I've been trying to do this for weeks now but every method i tried ended up crashing the app. Thank you in advance.