返回日期格式：2017-12-03T13:58:58.901Z，判断时间间隔 如 “刚刚”，“一分钟前”，“一小时前”等

后台返回的格式如下：

实现输出如下：

我的处理如下：

// 处理数据 2017-11-28T02:41:09.487Z
    // 请求的时间戳。日期格式按照ISO8601标准表示，并需要使用UTC时间。
    // 去掉.之后的字符串
    NSArray *strArray = [time componentsSeparatedByString:@"."];
    // 字符串转date
    NSDate *registerDate = [NSString dateFromString:[NSString stringWithFormat:@"%@Z",strArray[]]];
    // 对ISO8601标准时间date转String
    NSString *str = [NSString timeStamp:registerDate];
    // 对ISO8601标准时间String转时间间隔
    NSString *str1 = [NSString JudgmentTimeIntervalWithISOTime:str];
    self.registerTimeLabel.text = [NSString stringWithFormat:@"注册于：%@", [NSString compareCurrentTime:str1]];

具体的工具函数如下：

//方式一 后台给的格式为yyyy-MM-dd HH:mm:ss
+ (NSString *)compareCurrentTime:(NSString *)str {
    //把字符串转为NSdate
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSDate *timeDate = [dateFormatter dateFromString:str];
    NSDate *currentDate = [NSDate date];
    //得到两个时间差
    NSTimeInterval timeInterval = [currentDate timeIntervalSinceDate:timeDate];
    long temp = ;
    NSString *result;
    if (timeInterval/ < ){
        result = [NSString stringWithFormat:@"刚刚"];
    }
    else if((temp = timeInterval/) <){
        result = [NSString stringWithFormat:@"%ld分钟前",temp];
    }
    else if((temp = temp/) <){
        result = [NSString stringWithFormat:@"%ld小时前",temp];
    }
    else if((temp = temp/) <){
        result = [NSString stringWithFormat:@"%ld天前",temp];
    }
    else if((temp = temp/) <){
        result = [NSString stringWithFormat:@"%ld月前",temp];
    } else{
        temp = temp/;
        result = [NSString stringWithFormat:@"%ld年前",temp];
    }
    return  result;
}

//方式二 后台给的格式为 纯数字1352170595000(13位)
- (NSString *)updateTimeForRow:(NSString *)str {
    // 获取当前时时间戳 1466386762.345715 十位整数 6位小数
    NSTimeInterval currentTime = [[NSDate date] timeIntervalSince1970];
    // 创建歌曲时间戳(后台返回的时间 一般是13位数字)
    NSTimeInterval createTime =[str floatValue]/;
    // 时间差
    NSTimeInterval time = currentTime - createTime;

    //秒转分钟
    NSInteger small = time / ;
    if (small == ) {
        return [NSString stringWithFormat:@"刚刚"];
    }
    if (small < ) {
        return [NSString stringWithFormat:@"%ld分钟前",small];
    }
    // 秒转小时
    NSInteger hours = time/;
    if (hours<) {
        return [NSString stringWithFormat:@"%ld小时前",hours];
    }
    //秒转天数
    NSInteger days = time//;
    if (days < ) {
        return [NSString stringWithFormat:@"%ld天前",days];
    }
    //秒转月
    NSInteger months = time///;
    if (months < ) {
        return [NSString stringWithFormat:@"%ld月前",months];
    }
    //秒转年
    NSInteger years = time////;
    return [NSString stringWithFormat:@"%ld年前",years];
}

// ISO8601的Date转String
+ (NSString *)timeStamp: (NSDate *)date {
    // 获取当前时间
//    NSDate *date = [NSDate new];
    NSDateFormatter *timeFormatter = [NSDateFormatter new];
    [timeFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];
    [timeFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"];
    NSString *timestamp = [timeFormatter stringFromDate:date];
    return timestamp;
}

// String转Date
+ (NSDate *)dateFromString: (NSString *)str {
    NSDateFormatter *timeFormatter = [NSDateFormatter new];
    [timeFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];
    [timeFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"];
    return [timeFormatter dateFromString:str];
}

// ISO8601格式字符串转Date
+ (NSDate *)dateFromISO8601String:(NSString *)string {

    if (!string) return nil;
    struct tm tm;
    time_t t;
    strptime([string cStringUsingEncoding:NSUTF8StringEncoding], "%Y-%m-%dT%H:%M:%S%z", &tm);
    tm.tm_isdst = -;
    t = mktime(&tm);
    //    return [NSDate dateWithTimeIntervalSince1970:t]; // 零时区

    return [NSDate dateWithTimeIntervalSince1970:t + [[NSTimeZone localTimeZone] secondsFromGMT]];//东八区
}
//根据获取到的时间判断时间间隔 如 “刚刚”，“一分钟前”，“一小时前”等；
//获取时间 是用上面的方法获取的
+(NSString *)JudgmentTimeIntervalWithISOTime:(NSString *)timeStr{

    NSDate *theDate = [self dateFromISO8601String:timeStr];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString * timeString = nil;

    NSTimeInterval cha =   - [theDate timeIntervalSinceDate:[NSDate date]];
    if (cha/ < ) {
        timeString = [NSString stringWithFormat:@"%f", cha/];
        timeString = [timeString substringToIndex:timeString.length-];
        int num= [timeString intValue];
        if (num <= ) {
            timeString = [NSString stringWithFormat:@"刚刚"];
        }else{
            timeString = [NSString stringWithFormat:@"%@分钟前", timeString];
        }
    }
    if (cha/ >  && cha/ < ) {
        timeString = [NSString stringWithFormat:@"%f", cha/];
        timeString = [timeString substringToIndex:timeString.length-];
        timeString = [NSString stringWithFormat:@"%@小时前", timeString];
    }
    if (cha/ > ){
        timeString = [NSString stringWithFormat:@"%f", cha/];
        timeString = [timeString substringToIndex:timeString.length-];
        int num = [timeString intValue];
        if (num < ) {
            timeString = [NSString stringWithFormat:@"昨天"];
        } else{
            timeString =[dateFormatter stringFromDate:theDate];
        }
    }
    return timeString;
}

以前没遇到过这个格式的日期，今天算是长见识了，哈哈。希望你遇到这日期能看到我的博客，哈哈