Count if date is between two other dates (for entire columns of dates) - DIFFICULT

I need a graph which shows the number of delayed tasks over time based on a set of target and actual dates of completion.

Basically what I need to do is get a list of dates and the number of all tasks which were overdue on the respective date. The basis for this data is a table which lists all tasks with a column containing the respective targe date and another column containing the actual end date for each task.

Here's a simplified example:

Task ID	Target Date	Actual End Date
#1	01/01/2012	01/02/2012
#2	01/02/2012	01/02/2012
#3	01/03/2012	01/06/2012
#4	01/04/2012	01/05/2012

Date	No. of Tasks overdue	Task IDs of overdue Tasks
01/01/2012	0	-
01/02/2012	1	#1
01/03/2012	0	-
01/04/2012	1	#3
01/05/2012	2	#3,#4
01/06/2012	1	#3

The third column is not needed, I just added it to illustrate which columns were counted.

It is important that the solution DOES NOT involve a huge amount of cells filled with similar formulas (which would make the file large and calculations slow) or any VBA macros.

Ideally it should be a formula that counts how many times a given value is both larger than the left and smaller than the right cell value of each row of two neighbouring columns.

I would really appreciate any help on this as its starting to give me serious headaches

Deuces

Originally Posted by dilipandey

Completion for Task ID#1 was targeted at 01/01/2012 but completed at 01/02/2012.. hence on 01/01/2012.. this is one task over due and your table differs here.

That depends on your perspective. As I see it, task #1 was not (yet) overdue on 01/01/2012 (since that's the due date). It doesn't really matter though - I could easily adjust this by replacing > with >= in the formula (once I have a formula to work with )

Thanks for your help, please let me know if this needs further clarification.