countif function difficulty

I am trying to use the countif function. I have a list of dates in a seperate tab called wallchart. Now at the top of my main tab called POD I have a date function. When I put a date into it, it gives me todays date, yesterdays date and tomorrows date. Under yesterdays date I am trying to make a countif function that will count all the cells in "wallchart" that have the same date as that date.

Example:

Yesterday Today Tomorrow
Tuesday Wednesday Thursday
7/19/2011 7/20/2011 7/21/2011
My goal is to have the countif function to count all the cells in 'wallchart' that have yesterdays date in it. Then under the today cell I want to have all the dates with that date counted and same
with tomorrow.
This is an example of the wallchart tab.
Wallchart
7/5/2011
7/10/2011
7/8/2011
7/15/2011
7/19/2011
7/21/2011
7/20/2011
7/23/2011

I also want to be able to change the date and be able to count any cell with the date that I changed it to. so if I changed todays date to 7/23/2011, I would see a number 1 under the today cell. I dont know how to do this but any help would be greatly appreciated. If I wasnt clear enough let me know, and I will answer any questions people have.