/**
     * 0~23.
     * To avoid nightly promotion jobs running at the same time,
     * we run each branch on different hours.
     * master - 0:00
     * release - 1:00
     * release6x - 2:00
     * release7x - 3:00
     * ...
     * releaseNx - (N-4):00
     */
    val nightlyPromotionTriggerHour: Int? = determineNightlyPromotionTriggerHour(branchName)

    /**