Hello,

I have a category on NSDate, and I want to implement some functions to manipulate the date, like :

NSDate *thedate = [NSDate date];
[thedate setToMidnight];

so I have a function in NSDate like :

-(void)setToMidnight {
   some code with calendars and comps

   self = theNewDate;
}

This works inside the function, but outside this member function, thedate has not changed. I understand this malfunction because I've been told that self is just a local variable created inside the member function. So, how can I make this work ?

Of course, I could have written :

thedate = [thedate dateAsMidnightDate]
or thedate = [NSDate dateAtMidnightFromDate:thedate]

but I feel it has more sense inside the instance class, as I don't want to change the date but just adjust some values of the previously created one.

Can you help me to achieve this ?