The hour is defined via the variable "A3W_startHour", either in "server\init.sqf" from the PBO, or in the external "A3Wasteland_settings\main_config.sqf" from the main Arma 3 folder, if you grabbed it from our files repo on GitHub and placed it there before. The hour value in mission.sqm is always ignored.
Also, all config defined in "A3Wasteland_settings" is always read and takes precedence over the PBO, whether the mission is running as a dedi or self-hosted in game.