Sometimes we need day, hour, minute, second to countdown, but what we know just second.

For example:

* 1s -> 0day 0hour 0minute 1s
* 10s -> 0day 0hour 0minute 10s
* 100s -> 0day 0hour 1minute 40s

Here is my solution:

```swift
void _test() {
  var diffseconds = 100;

  var seconds = diffseconds % 60;
  var minute = diffseconds ~/ 60 % 60;
  var hour = diffseconds ~/ 60 ~/ 60 % 24;
  var day = diffseconds ~/ 60 ~/ 60 ~/ 24;

  print('day=$day');
  print('hour=$hour');
  print('minute=$minute');
  print('second=$seconds');
}

```

If I can change second to DateTime, I can get day easily with `date.day` and so on and I don't need to calculate anymore.

So I wonder is there any api or simple way to achieve it **without any calculate**.

I wonder better solution.