Hi Penny,
Section 594 of the Act is referring to postponement of rates under section 585 and the adjustments which should be made as a result of the redetermination of the attributable value.
Not sure exactly what you are asking here? Do you have a conservation agreement and need to back date it?
The % of land held under the Conservation agreement is exempt under sec 555(1)(b1) and the methodology for calculation under 555(3). I would back date the exemption to the date on the agreement with National Parks and Wildlife.
If you have had an objection or a reascertainment of the land value on a property with a conservation agreement you would have to recalculate the exemption as well.