Ind. Code § 36-2-6-14.5

Sec. 14.5. Notwithstanding any other provision of law, a special assessment required to be certified to the county auditor and added to the tax duplicate by law shall be certified within each county on or before a uniform date or dates established by the legislative body of that county. If the legislative body of a county does not establish a date for the certification required by this section, a special assessment required to be certified to the county auditor and added to the tax duplicate by law shall be certified on or before the assessment date.