Good things can come in small packages:
“Tempo was designed to work both in OSX and in iOS (7.0+). Work with the time or dates can be cumbersome, iOS development. Tempo allows you to deal easly with date and time. Basics manipulations are already implemented in Tempo.”
Libraries such as Tempo can be a huge timer saver when you need to do math with dates, for example, how many days is it from today until 12/31/2015.