It bugs on me ...

For those with ;-separator instead of ,-separator:

=IF(MONTH(DATE(YEAR(NOW());MONTH(NOW());1))-
MONTH(DATE(YEAR(NOW());MONTH(NOW());1)-
(WEEKDAY(DATE(YEAR(NOW());MONTH(NOW());1))-1)+
{0;1;2;3;4;5}*7+{1;2;3;4;5;6;7}-1);"";DATE(YEAR(NOW());
MONTH(NOW());1)-(WEEKDAY(DATE(YEAR(NOW());
MONTH(NOW());1))-1)+{0;1;2;3;4;5}*7+{1;2;3;4;5;6;7}-1)

But on my first and last row I do not get anything.
On row 2 I got all mondays (all the same), row3: all the same
tuesdays, row4: wedns, row5: thursds
like:
....
ma 05-sep-05 ma 05-sep-05 ma 05-sep-05 ...
di 13-sep-05 di 13-sep-05 di 13-sep-05 ...
....
in 7 columns though.

Strange, strange, strange...