Please Help. Filter calculated field for a given date range

You may have to rethink the way you count presence and absence as your checkbox only check for people being present but the absent is in another column so your result is only going to be present.

Usually we use a boolean non null field with a default value for present or absent, if present, set a 1 otherwise it is a 0 and then counting people becomes easier. You can replace 1 and 0 by anything you want in your project.

Hi Iacobescubogdan,
Welcome to MVD.
I had to change your original project a bit - it's not usually a good idea to try and combine data maintenance (add, edit, delete)  and data display / enquiry / filter all on the same form.  It results in a lot of extra coding to validate your data (blank and duplicate records are the main problem).  In your example, you also use comboboxes for both data input and for data filtering which can be confusing for users.
Please have a look at the attachment.  I've used 2 tablegrids on your 'grupavasile' form so you can see the employee summary and employee details at the same time (and it's easier to test (LOL!) that the filters and dates are working properly.  But it's easy enough to change the layout to suit your requirement - the basic processing is in place.
The employee summary (by selected date range) has to use an 'sqlquery' and there is also a small amount of code in the script (not strictly necessary - it just automates what you'd otherwise have to do manually.
Hope this helps,
Derek.