ios日期时间处理

//2015-09-15 18:09:28 - 1442311768
    NSLog(@"2015-09-15 18:09:28");
    NSDate *createTimesp =
     [NSDate dateWithTimeIntervalSince1970:1442311768+28800];
    NSLog(@"%@",createTimesp);
    
    NSString *str=@"1442311768";//时间戳
    NSTimeInterval time =
     [str doubleValue]+28800;//因为时差问题要加8小时 == 28800 sec
    NSDate *detaildate=[NSDate dateWithTimeIntervalSince1970:time];
    NSLog(@"%@",[detaildate description]);
    
    //实例化一个NSDateFormatter对象
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    //设定时间格式,这里可以设置成自己需要的格式
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString *currentDateStr = 
        [dateFormatter stringFromDate:
            [NSDate dateWithTimeIntervalSince1970:1442311768]];
    NSLog(@"%@",currentDateStr);
    //NSLog(@"%ld",(long)[[NSDate date] timeIntervalSince1970]);

结果：

2015-09-16 11:14:18.433 test[647:8649] 2015-09-15 18:09:28
2015-09-16 11:14:18.435 test[647:8649] 2015-09-15 18:09:28 +0000
2015-09-16 11:14:18.435 test[647:8649] 2015-09-15 18:09:28 +0000
2015-09-16 11:14:18.436 test[647:8649] 2015-09-15 18:09:28