android - generate random date and time

Question

to trigger some future events I'm trying to create an algorithm which would do the following:

• generate a certain amount of random dates in format "yyyy-mm-dd"
• generate time for each date in format "hh:mm:ss" Time should be (24h) between 9 and 22 hours
• Add those items to a String array. 1 complete array entry looks like "2013-02-25 09:45:23"

I have no clear ideas how to perform this. Any suggestions?

Answer 1

Exact Solution what you need..

public class RandomDateTime {

    public static void main(String[] args) {

        SimpleDateFormat dfDateTime  = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss",Locale.getDefault());
        int year = RandomDateTime.randBetween(1900, 2013);// Here you can set Range of years you need
        int month = RandomDateTime.randBetween(0, 11);
        int hour = RandomDateTime.randBetween(9, 22); //Hours will be displayed in between 9 to 22
        int min = RandomDateTime.randBetween(0, 59);
        int sec = RandomDateTime.randBetween(0, 59);


        GregorianCalendar gc = new GregorianCalendar(year, month, 1);
        int day = RandomDateTime.randBetween(1, gc.getActualMaximum(gc.DAY_OF_MONTH));

        gc.set(year, month, day, hour, min,sec);

        System.out.println(dfDateTime.format(gc.getTime()));

    }


    public static int randBetween(int start, int end) {
        return start + (int)Math.round(Math.random() * (end - start));
    }
}

You can find out more uses of SimpleDateTime at: http://docs.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html

Answer 2

what you can do is using the random function get the random timestamp, I mean you can get the random long value easily and then convert that timestamp to the date object like this

Java simple Timestamp to Date conversion