NSDate存储的是世界标准时(UTC)，输出时需要根据时区转换为本地时间

+ (NSDate *)tDate{

    NSDate *date = [NSDate date];

    NSTimeZone *zone = [NSTimeZone systemTimeZone];

    NSInteger interval = [zone secondsFromGMTForDate: date];

    NSDate *localeDate = [date  dateByAddingTimeInterval: interval];

    NSLog(@"%@", localeDate);

    return localeDate;

}