Hi to all, I am italian and I write from Spain

=IF(1<=I6<=6;"1"),IF(7<=I6<=12;"2");"3")

I would:
if I6 is > = 1 and < = 6 write 1 in I7
If I6 > = 7 and > = 12 write 2 in I7
If none write 3 in I7

Why doesn't work??

If I have in A1 a date, for example monday 21 april 2011, I want that in A2 it write 1 (first day of week), if it is tuesday write 2, and so on... how make it?
It has to work with excel of other language where for example in spanish monday is lunes and so on...
Thanks