JS: Convert Milliseconds to days? minutes? seconds? or all!

ConvertMS.js

function convertMiliseconds(miliseconds, format) {
  var days, hours, minutes, seconds, total_hours, total_minutes, total_seconds;
  
  total_seconds = parseInt(Math.floor(miliseconds / 1000));
  total_minutes = parseInt(Math.floor(total_seconds / 60));
  total_hours = parseInt(Math.floor(total_minutes / 60));
  days = parseInt(Math.floor(total_hours / 24));

  seconds = parseInt(total_seconds % 60);
  minutes = parseInt(total_minutes % 60);
  hours = parseInt(total_hours % 24);
  
  switch(format) {
	case 's':
		return total_seconds;
	case 'm':
		return total_minutes;
	case 'h':
		return total_hours;
	case 'd':
		return days;
	default:
		return { d: days, h: hours, m: minutes, s: seconds };
  }
};

Good job!
Principle : "Fail fast and early if you have to and recover soonest"
So I'll suggest you return zero on the third line if the milliseconds argument is zero, or any out of order input.
Some sort of error handling I suppose.
It saves on infrastructure cost and improves app performance when the other lines of code don't have to pointlessly run .
Like so .......

Thanks a lot!

Thanks a bunch!