Apart from the concept of space being a main concern of spatial planning, the concept of time, too, has a role. Not only by setting time limits to substantive plans; planning is also subject to time and the implications of this are analysed in this paper. Planning instruments age and need cyclic maintenance for staying effective, a process referred to as iterative adaptation. But adaptation may not be sufficient when society has evolved too far away from the situation of the instrument's conception, whereby not only the content of plans should be considered (corresponding with substantive needs of society) but the intervention philosophy as well (corresponding with the image society has about the proper role of the government). In addition, each iterative adaptation takes time that may prove to be insufficient in a dynamic context. This paper refers to the rural planning instrument called land consolidation to demonstrate how time has moulded it and what the limitations for adaptation are.