Question

I am developing a Java Swing application which sends a report on a specific day and time of a week, say for example the report time is Wed 09:00:00. I am trying to calculate the time difference between current Day and time with report Time. For example:

DayTime1 = “Wed 09:00:00”
DayTime2 = “Tue 13:00:00”

How do I calculate the time difference between these two values? I tried by myself, but I couldn’t even get close to the result.

Answer 1

You need to create the String into Date objects and then calculate the duration between the two instances.

DateFormat dateformat = new SimpleDateFormat("EEE HH:mm:ss");
Date date1 = dateformat.parse(dayTime1);
Date date2 = dateformat.parse(dayTime2);
getDuration(date1, date2, Calendar.MINUTE);

public static long getDuration(Date returnTime, Date leaveTime, int scale) {
        long durationInMillis = returnTime.getTime() - leaveTime.getTime();
        switch (scale) {
            case Calendar.MINUTE:
                return durationInMillis / ONE_MINUTE_IN_MILLIS;
            case Calendar.MILLISECOND:
                return durationInMillis;
            case Calendar.SECOND:
                return durationInMillis / ONE_SECOND_IN_MILLIS;
            case Calendar.HOUR:
                return durationInMillis / ONE_HOUR_IN_MILLIS;
            case Calendar.DAY_OF_YEAR:
            case Calendar.DATE:
                return durationInMillis / ONE_DAY_IN_MILLIS;
        }
        throw new IllegalArgumentException("invalid scale specified");
    }