De or het kalendercommissie?

The correct Dutch article is:

de kalendercommissie

Rule Words ending in -tie and -sie: almost always de. See the rule

How to use kalendercommissie

the kalendercommissiede kalendercommissie
this kalendercommissiedeze kalendercommissie
that kalendercommissiedie kalendercommissie
our kalendercommissieonze kalendercommissie
your kalendercommissiejouw kalendercommissie
every kalendercommissieelke kalendercommissie
which kalendercommissie?welke kalendercommissie?
a big kalendercommissie / the big kalendercommissieeen grote kalendercommissie, de grote kalendercommissie