Thanks for all your answers.
I only wanted calendar in month view to be less wide. I have problem when viewing on smartphone. Calendar tab doesn't fit the screen width... and the right part (sunday column view) is not complete...
Never mind...
I would be very happy if this option (hide weekend days) could be ticked or something like.
About UX, i would prefer (depends on my professional category) weekend days not to appear, hide columns that are always empty...
Thanks for all...