"They are going away on Thursday."
Translation:De reiser bort på torsdag.
We can see why 'går' doesn't work here, but could you also use 'dra bort' in place of 'reiser bort' in this sentence? Let's say, for example, the subjects aren't traveling a long distance, but are moving out, to another house not too far away: "Når dra de bort fra dette huset?" "De dra bort på torsdag."