La concaténation et l’accès aux variables du contexte flow ça ne marche pas comme ça dans jsonata.
Si tu affiches {"start_date_time":flow.journee,"duration":"23:59:00"}
dans un noeud debug, ça ne va pas avoir le format voulu.
Ou veux tu configurer la date de début, de fin et les heures ?
J’aurais tendance à faire ça avec un input_date :
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