De or het weekindeling?

The correct Dutch article is:

de weekindeling

Rule Words ending in -ing: almost always de. See the rule

How to use weekindeling

the weekindelingde weekindeling
this weekindelingdeze weekindeling
that weekindelingdie weekindeling
our weekindelingonze weekindeling
your weekindelingjouw weekindeling
every weekindelingelke weekindeling
which weekindeling?welke weekindeling?
a big weekindeling / the big weekindelingeen grote weekindeling, de grote weekindeling