Person.h

@interface Person : NSObject <NSCoding>

- (id)initWithName:(NSString*)name birthDate:(NSString*)birthDate;

@property (nonatomic, copy, readonly) NSString* name;
@property (nonatomic, strong, readonly) NSDate* birthDate;

@end

Person.m

#import "Person.h"

static NSString* const kName = @"name";
static NSString* const kDate = @"date";

@implementation Person

- (id)initWithName:(NSString*)name birthDate:(NSString*)birthDate {
  self = [super init];
  if(self) {
    _name = [name copy];
    _birthDate = birthDate;
  }
  return self;
}

- (id)initWithCoder:(NSCoder*)aDecoder {
    self = [super init];
    if (self) {
      _name = [aDecoder decodeObjectForKey:kName]; 
      _date = [aDecoder decodeObjectForKey:kDate]; 
    }
    return self;
}

- (BOOL)isEqual:(id)obj {
  if(![obj isKindOfClass:[Person class]]) return NO;
 
  Person* other = (Person*)obj;
  BOOL nameIsEqual = _name == _other->_name || [_name isEqual:other->_name];
  BOOL dateIsEqual = _date == _other->_date || [_date isEqual:other->_date];
  return nameIsEqual && dateIsEqual;
}

- (void)encodeWithCoder:(NSCoder*)aCoder {
  [aCoder encodeObject:_name forKey:kName];
  [aCoder encodeObject:_date forKey:kDate];
}

@end