Adding up dates from multiple tabs

Hello, we keep a daily census of patients that are enrolled in research studies. Each study has a tab with the patient's admission date along with a date for each day they are on our unit. The enclosed spreadsheet has two studies and an analysis tab. On the analysis tab, I want to be able to count the dates for a particular day. So on May 20th, we had 4 patients on our research unit. Each patient enrolls at different dates, and has a different enrollment date, so the 5/20/14 dates are in different cells in different tabs. How do I count the dates?
Thank you.

This is what six is talking about above. The use of whole column references is convenient but inefficient. It is better to have defined ranges but easier to enter if those ranges were the SAME dimension as you could use copy and paste:

Formula:

Please Login or Register  to view this content.

This might also be of interest. Just add the worksheet names along the row with the worksheet names and copy the formula across and down.

You will save yourself a lot of work if you just define the ranges on each worksheet to be large enough and equal to each other to handle the largest of the worksheets.

In the workbook that I uploaded to you, all you have to do to include a new study is to add the name of the worksheet in the row with the worksheet names and copy the formula over. The formula will recognize the worksheet from the name you enter and fill in the data for you.

To make the formula work with your actual data, change the $F$100 to the lower right limit of what will exceed what you think that you will need. For example it might be something like $M$20000 which would cover 12 subjects for 54 years!

Planning ahead will save you a lot of work.