Taxes are due and payable quarterly on the first day of February, May, August and November, after which time they are delinquent and subject to interest at the rate of 8% on the first $1500 and 18% over $1500. You have a 10-day grace period to pay taxes with no penalty, after which interest will accrue back to the actual due date. If the 10-day grace period falls on a Saturday or Sunday, you may make payment by 4:30 pm on the next business day with no penalty.