Copying an NSDate (wanting independent objects)

Question

NSDate conforms to NSCopying protocol. According to the documentation for NSCopying protocol:

a copy must be a functionally independent object with values ident         


        

Answer 1

Beware!

I recently found out, that on iOS 8.1(.0) [NSDate dateWithTimeInterval:0 sinceDate:date1] returns date1! Even the alloc/init returns the same object.

The deep-copy was important for me, as I create copies of objects. Later I compare the timestamps with [date1 laterDate:date2] == date2 which will always be true, if the deep-copy doesn't work.

Same for [date1 dateByAddingTimeInterval:0]

I have no good solution for iOS 8.1, yet, but keep searching and will update here. An emergency-workaround could be to create a date-string with a formatter, and then create a date from the string with the same formatter.

Edit: It get's even worse:

NSString *date1String = [iso8601DateFormatter stringFromDate:date1];
date2 = [iso8601DateFormatter dateFromString:date1String];

(lldb) p date1
(NSDate *) $0 = 0xe41ba06fd0000000 2014-11-03 01:00:00 CET
(lldb) p date2
(NSDate *) $1 = 0xe41ba06fd0000000 2014-11-03 01:00:00 CET