Protocol Naming in Objective C

I’m struggling with naming protocols in Objective-C. For example:

I have a protocol called Command.
I have an abstract class that implements Command that is a base class for my concrete Commands.

I …

Difference between two NSDates

I am taking two NSDates by using date time picker. Now I want to count the number of days between these two NSDates. How can I find the difference between two NSDates.

please give me some solution.