If the event is just 2 hours long, keep the intro and the closing short. If you spend 2.5 hours or more, you can spend more time on the closing. If the event is even longer, consider running something by the middle of it, to give people a moment to step away from the project.
Ma yella tadyant tettaṭṭaf kan 2 n yisragen, eǧǧ tazwart d taggara d tiwezlanin. Ma yella teṭṭfeḍ 2.5 n yisragen neɣ ugar, tzemreḍ ad as-tefkeḍ ugar n wakud i taggara. Ma yella tadyant ɣezzifet aṭas, muqel amek ara tt-tgezmeḍ s kra, akken ad sgunfun cwiṭ yimdanen seg usenfar.