In order to pay the current year's Hawaii real estate taxes in one payment without having to pay a penalty and interest on the taxes, when must the taxes be paid?

To avoid penalties and interest on Hawaii real estate taxes, they must be paid by a specific date within the current year. In Hawaii, property taxes are typically due in two installments: the first half is due on August 20, which is within the current tax year. Paying by this deadline allows property owners to fulfill their tax obligations without incurring any penalties or interest.

Paying after this date would result in late fees, thus it’s critical to meet this timeline. The other options represent dates outside the permissible range for timely payment, leading to assessments of penalties. Therefore, paying the current year's taxes by August 20 is essential for avoiding these additional costs.