Chewing tobacco packing machine duty is calculated monthly; new manufacturers pay a pro-rata first-month duty within five days of installation. Duty for chewing tobacco, jarda scented tobacco and gutkha packing machines is calculated monthly by applying the notified rate; for a new manufacturer the first month's duty is determined on a pro-rata basis based on days from installation and must be paid within five days of installation. Where machine numbers change during a month, the number used for the month's duty calculation is the maximum installed on any day of that month.