Lacrifilm Lacrifilm - 1 year ago 76
Objective-C Question

initWithTimeIntervalSinceReferenceDate return null when the year is less than 2000

I have this code below that storage my date from date picker:

uint64_t offset = (uint64_t)[[self.dataPicker date] timeIntervalSinceReferenceDate];
// store this 64-bit unsigned integer.

NSLog(@"Offset -> %llu",offset);

To convert date format again I use the following command:

NSDate *data = [[NSDate alloc] initWithTimeIntervalSinceReferenceDate:offset];
NSLog(@"Before -> %@",data);

But this code has a problem, the command
always return null when I select a smaller year than 2000 (1999,1998,1997 ...), but the
is still to store a value.

What is happening and how can I solve this problem?

Answer Source

Consider these facts:

  • The reference date is Jan 1, 2001.
  • All time interval values before that date are negative.
  • You are using the type uint64_t which can never be negative.

There is a dedicated type NSTimeInterval (aka double).

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