From string to date format

Question

I have 2 strings (eg: "1232" and "1332"). These 2 strings are values of an hour (12h32 and 13h32). Important is that these values are not always the same.
Now what I have to do is to calculate some given numbers between these hours.
Example:
Let's take the 2 hours mentioned above: 12h32 and 13h32.
And I have to calculate 10 numbers between these hours.
I have to take every 6 minutes of the given hour: 12h38,12h44,...
When I have calculate the numbers I have to give back a string "1238","1244"
How can I put the the strings into the dateformat 'HH:MM' and visa versa?
Or is there a better way to calculate these numbers?
can someone help me,please?
Thanks in advance!!!

Answer 1

A small example:public class Test {
    private LTime startTime;
    private LTime endTime;
    private int count;
    public Test (String startTime, String endTime, int count) {
        this.startTime = new LTime (startTime);
        this.endTime = new LTime (endTime);
        this.count = count;
    public String[] getTimesBetween () {
        String[] timesBetween = new String[count - 1];
        LTime lTime = new LTime (startTime);
        int minutesBetweenStartAndEnd = startTime.getMinutesBetween (endTime) / count;
        for (int i = 0; i < count; i ++) {
            if (i > 0) {
                timesBetween[i - 1] = lTime.toString ();
            lTime.add (0, minutesBetweenStartAndEnd);
        return timesBetween;
    private class LTime {
        private int hours;
        private int minutes;
        public LTime (String lTime) {
            this (Integer.parseInt (lTime.substring (0, lTime.indexOf ("h"))), Integer.parseInt (lTime.substring (lTime.indexOf ("h") + 1)));
        public LTime (LTime lTime) {
            this (lTime.hours, lTime.minutes);
        public LTime (int hours, int minutes) {
            this.hours = hours;
            this.minutes = minutes;
        public int getHours () {
            return hours;
        public int getMinutes () {
            return minutes;
        public void add (int hours, int minutes) {
            this.minutes += minutes;
            this.hours += hours + this.minutes / 60;
            this.minutes %= 60;
        public int getMinutesBetween (LTime lTime) {
            return isAfter (lTime) ? (hours - lTime.hours) * 60 + minutes - lTime.minutes : lTime.getMinutesBetween (this);
        public boolean isAfter (LTime lTime) {
            return (hours > lTime.hours) || ((hours == lTime.hours) && (minutes > lTime.minutes));
        public String toString () {
            return fill (hours) + "h" + fill (minutes);
        private String fill (int i) {
            return i < 10 ? "0" + i : String.valueOf (i);
    public static void main (String[] parameters) {
        String[] timesBetween = new Test ("8h30", "16h30", 12).getTimesBetween ();
        for (int i = 0; i < timesBetween.length; i ++) {
            System.out.print (((i == 0) ? "" : ", ") + timesBetween);
}You might want to fix the following issues:
* the count is not correct: if you specify 10, you get 9
* the time class is for some reason named LTime
* Because of the int division, you can get enormous
differences between the end time that getTimesBetween ()
returns and the actual end time
Of course, I could have gotten rid of these myself, but
it's your homework...
Kind regards,
  Levi