java dates

[Jason Crest]

How do i go about taking a date in the format 2004-09-07 then subtract 4 days from it and put it back in the same format? it should look like 2004-09-03

[Adeel Ansari]

you can use java.text.SimpleDateFormat class to format your date.

get the milliseconds by using sdf.getTime(). convert your 4 days into milliseconds and then take the difference. and format it again to represent a date. enjoy.

Moreover, read the javadocs for SimpleDateFormat. it will guide you through
[ September 08, 2004: Message edited by: adeel ansari ]

[JulianInactive KennedyInactive]

Hi Jason,

You should read the API docs for Calendar too. Here's some bonus code as I'm feeling charitable:

String today = "2004-09-07";
String[] part = today.split("-");
int year  = Integer.parseInt(part[0]);
int month = Integer.parseInt(part[1]) - 1; // Months start at 0
int day   = Integer.parseInt(part[2]);
Calendar cal = new GregorianCalendar(year, month, day);
cal.add(Calendar.DATE, -4);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(sdf.format(cal.getTime())); // prints 2004-09-03

It's not as straightforward as you might think, is it? I'll leave any error handling to you.

Jules