Need help with calendar algorithm

Question

I am trying to create a gag calendar app and need some help getting the algorithm correct to create a calendar like this:

Sunday
Jan Feb .. Dec
  2   6      4
  9  13     11
 16  20     18
 23  27     25
 30

Monday
Jan Feb .. Dec
  3   7      5
 10  14     12
 17  21     19
 24  28     26
 31

And so on... I have the code from http://helpdesk.objects.com.au/java/display-a-month-as-a-calendar

But can't get the algorithm to do it like above.

what does your algorithm do at the moment? In what way is it not working. We can't help if you don't give us some clues. — Sam Holder, Apr 05 '11 at 15:03
Have a look at this to see how to get the first weekday of a month, then for each new row just add 7 days to the previous row. http://stackoverflow.com/questions/924246/get-the-first-or-last-friday-in-a-month/924276#924276 — Mark Ransom, Apr 05 '11 at 15:39
@Sam Holder, the code just prints a standard calendar of months. What I'm looking for is different as you can see. — MB34, Apr 05 '11 at 15:42
@MB34, why not? First row, display the first Sunday in Jan, first Sunday in Feb, etc. Second row show the second Sunday in Jan, second Sunday in Feb, etc. The method I linked will get the first, second, etc. specific day of any given month. — Mark Ransom, Apr 05 '11 at 15:46
@MB34 that's too complicated? not sure how we can help if a fairly straightforward answer is too complicated. — Sam Holder, Apr 05 '11 at 15:53
Another option is to build a set of nested objects, we used ArrayLists. It's a little grungy but the basic structure is ArrayList>> and represents a nested structure of month>; i.e. January, Tuesday<2,8,15,22,29>... Populate the required timespan up front and then display. — karakuricoder, Apr 05 '11 at 16:31

score 1 · Accepted Answer · answered Apr 05 '11 at 16:51

Model the desired output as a three-dimensional array

private static final int DAYS_IN_WEEK = 7;
private static final int WEEKS_IN_MONTH = 5;
private static final int MONTHS_IN_YEAR = 12;
Integer dayNumber[DAYS_IN_WEEK][WEEKS_IN_MONTH][MONTHS_IN_YEAR];

Allocate it and fill it using standard Calendar methods that give you the indices, then iterate over it in row-major order to produce the output.

Need help with calendar algorithm

1 Answers1