Chewing tobacco packing machines: abatement is a pro rata excise adjustment based on machine downtime days in the month. The abatement amount equals the excise duty liability for the machine for the month multiplied by the total number of continuous days the machine was inoperative in the month, divided by the total number of days in the month, providing a days-based pro rata apportionment of duty for chewing tobacco, jarda, scented tobacco and gutkha packing machines under the Capacity Determination and Collection of Duty Rules.