Percentage between two dates compared to today in android/java

Question

How I can find percentage between two dates compared to today in android/java? This question is based on this question.

I want to do something like this:

    Calendar c = Calendar.getInstance();
    yeartoday = c.get(Calendar.YEAR);
    monthtoday = c.get(Calendar.MONTH);
    daytoday = c.get(Calendar.DAY_OF_MONTH);
...

    Date datestart = getDate(styear,(stmonth-1),stday);
    Date dateend = getDate(year,(month-1),day);
    Date datetoday = getDate(yeartoday,monthtoday,daytoday);
    double percent = (((datetoday - datestart) / (dateend - datestart)) * 100);
...
public Date getDate(int year,int month,int day){
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.YEAR, year);
    calendar.set(Calendar.MONTH, month);
    calendar.set(Calendar.DAY_OF_MONTH, day);
    Date date = calendar.getTime();
    return date;
}

Answer 1

That's what I did:

    double millisstart = datestart.getTime();
    double millisend = dateend.getTime();
    double millistoday = datetoday.getTime();
    double percent = (((millistoday - millisstart) / (millisend - millisstart)) * 100);
    percentAsString = Double.toString(percent);

    txt5.setText(percentAsString);