"They watch TV the whole week, but never use their computers."
Translation:De ser tv hele ugen, men bruger aldrig deres computere.
I think - that definite article is not needed when another word 'defines' the noun. It is like Mine börn, does not need article, since the children is defined by 'mine'. So the week, ugen, is defined by 'hele', it is enough. We do the same thing in Swedish (hela veckan - no def. art.).