Number Of Hour Worked

Hello!!!
I've a trouble:
I have an Access DataBase with two tables:
1--Workers with fields (ID, Name and $/hour)
2--Marks with fields(ID, WorkerID, Datetime of mark)

Well, I need to generate a report with the following structure:

Name Worker / Number of days worked / Total Cost in $
---------------------------------------------------------------------------
Worker 1 / 19 / 13000$
Worker 2 / 20 / 21354$
Worker 3 / 12 / 12000$
...

Example of Workers Table Data:
ID / Name / $/hour
-------------------------------------------------------------------------
21367 / Worker 1 / 21,34$
54883 / Worker 2 / 54,87$
87364 / Worker 3 / 5,38$

Example of Marks Table Data:
ID / IDWorker / DateTime-Mark
-------------------------------------------------------------------------
6754-54 / 21267 / 19/05/2006 8:05:32
4327-12 / 54883 / 19/05/2006 8:07:12
7645-98 / 87364 / 19/05/2006 8:13:54
5432-99 / 21267 / 19/05/2006 14:05:32
7584-23 / 54883 / 19/05/2006 14:07:12
9485-23 / 87364 / 19/05/2006 14:13:54
... / 21267 / 19/05/2006 16:05:32
... / 54883 / 19/05/2006 16:07:12
... / 87364 / 19/05/2006 16:13:54
... / 21267 / 19/05/2006 20:05:32
... / 54883 / 19/05/2006 20:07:12
... / 87364 / 19/05/2006 20:13:54
... / 21267 / 20/05/2006 8:05:32
... / 54883 / 20/05/2006 8:07:12
... / 87364 / 20/05/2006 8:13:54
... / 21267 / 20/05/2006 14:05:32
... / 54883 / 20/05/2006 14:07:12
... / 87364 / 20/05/2006 14:13:54
... / 21267 / 20/05/2006 16:05:32
... / 54883 / 20/05/2006 16:07:12
... / 87364 / 20/05/2006 16:13:54
... / 21267 / 20/05/2006 20:05:32
... / 54883 / 20/05/2006 20:07:12
... / 87364 / 20/05/2006 20:13:54

The condition to increment number of days is:
YEAR(date-mark) != YEAR(date-mark) OR
MONTH(date-mark) != MONTH(date-mark) OR
DAY(date-mark) != DAY(date-mark)

for example:
1)
19/05/1982...time-mark // Worker 1
19/05/1982...time-mark // Worker 1
19/05/1982...time-mark // Worker 1
19/05/1982...time-mark // Worker 1
-----------------------------------> 1 days worked
2)
20/05/1982...time-mark // Worker 1
20/05/1982...time-mark // Worker 1
21/05/1982...time-mark // Worker 1
21/05/1982...time-mark // Worker 1
-----------------------------------> 2 days worked

Do you understand it?

Well, I've tried several SQL sentences, but I can't make the definitive sentence. Can you help me, please?

Note --> each Mark-Datetime represents an instant of time!!!