dateformatter.m

- (NSDate *)dateFromString:(NSString *)dateString
{
    NSString *dt_format_string = @"yyyy-MM-dd'T'HH:mm:ss";
    NSDateFormatter *dtFormat = [[NSDateFormatter alloc]init];
    [dtFormat setDateFormat:dt_format_string];
    NSCalendar *gregorian = [NSCalendar calendarWithIdentifier:NSCalendarIdentifierGregorian];
    dtFormat.calendar = gregorian;
    NSLocale *enUSPOSIXLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
    dtFormat.locale = enUSPOSIXLocale;
    
    NSDate *date = [dtFormat dateFromString:dateString];
    return date;
}

read_cyling_data.m

/**
 Read Cycling Distance
 */
- (void)readCyclingDistanceWithFinishBlock:(void (^)(NSError *error, NSNumber *value))finishBlock
{
    // start date
    NSDate *startDate = [self dateFromString:@"2018-05-08T00:00:00"];
    
    // end date
    NSDate *endDate = [self dateFromString:@"2018-05-08T23:59:59"];
    
    // Sample type
    HKSampleType *sampleCyclingDistance = [HKSampleType quantityTypeForIdentifier:HKQuantityTypeIdentifierDistanceCycling];
    
    // Predicate
    NSPredicate *predicate = [HKQuery predicateForSamplesWithStartDate:startDate
                                                               endDate:endDate
                                                               options:HKQueryOptionStrictStartDate];
    
    // valud
    __block float dailyValue = 0;
    
    // query
    HKSampleQuery *query = [[HKSampleQuery alloc] initWithSampleType: sampleCyclingDistance
                                                           predicate: predicate
                                                               limit: 0
                                                     sortDescriptors: nil
                                                      resultsHandler:^(HKSampleQuery *query, NSArray* results, NSError *error){
                                                          
                                                          dispatch_sync(dispatch_get_main_queue(), ^{
                                                              if (error) {
                                                                  
                                                                  NSLog(@"error");
                                                                  finishBlock(error, nil);
                                                                  
                                                              } else {
                                                                  
                                                                  for(HKQuantitySample *samples in results)
                                                                  {
                                                                      dailyValue += [[samples quantity] doubleValueForUnit:[HKUnit mileUnit]];
                                                                  }
                                                                  
                                                                  finishBlock(nil, @(dailyValue));
                                                              }
                                                          });
                                                      }
                            ];
    
    // execute query
    [self.healthStore executeQuery:query];
}