@freq_interval должен быть от 1 до 10 (1 = воскресенье. 7 = суббота, 8 = день, 9 = день недели, 10 = выходной день) для связанного ежемесячного задания.
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English version
@freq_interval must be between 1 and 10 (1 = Sunday .. 7 = Saturday, 8 = Day, 9 = Weekday, 10 = Weekend-day) for a monthly-relative job.