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Java Calendar date interval

Can someone please provide me code to help me achieve the following:

Given any date (example: 02-12-2009), I'd like to return String array where the first value of the array is the first date in the associated week (02-08-2009) and the second value is the last date in the associated week (02-14-2009). This would be based on a week that starts on Sunday and ends on Saturday every time. Also, I need this to work during leap years and non-leap years. Thanks for your help.

Mick Barry

see the following for getting the first day of the week

http://helpdesk.objects.com.au/java/how-do-i-get-the-date-of-first-day-of-the-current-week

you can then just loop adding a day each time and using a DateFormat to format the date.

http://helpdesk.objects.com.au/java/how-do-i-format-a-date-as-a-string

Let me know if you need a hand putting it all together

jrwalker2

ASKER

I attached my code so far. I have not gotten it to work yet. I have a few problems. First, when I create the initial Gregorian calendar, it does not appear to be following the 0-based month as stated in the javadoc. Second, the first day and the last day in the associated week are not correct. Please help. Thanks

Actual Output
------------------
Current date: 1/19/2009
First day of week: 1/26/2009
Last day of week: 2/5/2009

Expected Output
-------------------
Current date: 2/19/2009 <-------------I thought that GregorianCaledar month is 0-based (i.e., Feb=1)
First day of week: 2/15/2009 <----------This is the Sunday of that week
Last day of week: 2/21/2009 <------------This is the Saturday of that week

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.SimpleTimeZone;
import java.util.TimeZone;
 
public class DateUtil 
{
 
	public static void main(String [] args)
	{
		 //Input: February 19, 2009
		GregorianCalendar calendar = new GregorianCalendar(2009,1,19);
		 
		 //Get the interval
		DateUtil dateUtil = new DateUtil();
		String [] interval = dateUtil.getWeekInterval(calendar);
 
		System.out.println("First day of week: " + interval[0]);
		System.out.println("Last day of week: " + interval[1]);
	}
	
	private String[] getWeekInterval(GregorianCalendar cal)
	{
		int day;
		int month;
		int year;
		String firstDate;
		String lastDate;
		
		
		//Current date 
		day = cal.get(Calendar.DAY_OF_MONTH);
		month = cal.get(Calendar.MONTH);
		year = cal.get(Calendar.YEAR);
		System.out.println("Current date: " + month +"/"+day+"/"+year);
		
		//First Day of the week 
		Calendar firstDateofTheWeek = getFirstDayOfThisWeek(cal);
		day = firstDateofTheWeek.get(Calendar.DAY_OF_MONTH);
		month = firstDateofTheWeek.get(Calendar.MONTH);
		year = firstDateofTheWeek.get(Calendar.YEAR);
		firstDate = month +"/"+day+"/"+year;
		
		//Last Day of the week 
		Calendar lastDateofTheWeek = getLastDayOfThisWeek(cal);
		day = lastDateofTheWeek.get(Calendar.DAY_OF_MONTH);
		month = lastDateofTheWeek.get(Calendar.MONTH);
		year = lastDateofTheWeek.get(Calendar.YEAR);
		lastDate = month +"/"+day+"/"+year;
		
		String [] interval = {firstDate,lastDate};
		
		
		return interval;
	}
	
	private Calendar getFirstDayOfThisWeek(GregorianCalendar cal) 
	{
		cal.add(Calendar.DAY_OF_YEAR, Calendar.SATURDAY);
 
		return cal;
	}
	
	private Calendar getLastDayOfThisWeek(GregorianCalendar cal) 
	{
		cal.add(Calendar.DAY_OF_YEAR, Calendar.SATURDAY);
 
		return cal;
	}
	
}

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Mick Barry

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jrwalker2

ASKER

This is great!!! The only thing that I had to change

return new String[] { df.format(start), df.format(end) };

to

return new String[] { df.format(start.getTime()), df.format(end.getTime()) };

I had to do this in order to use the formatter. Thank you! Your help is very much appreciated.

Mick Barry

I made that mistake on purpose to make sure you understood how it worked ;)