In this paper, I discuss whether there are genuinely *diachronic* constraints of practical rationality, that is, pressures on combinations of practical attitudes over time, which are not reducible to mere synchronic rational pressures. Michael Bratman has recently argued that there is at least one such diachronic rational constraint that governs the stability of intentions over time. *Pace* Bratman, I argue that there are no genuinely diachronic constraints on intentions that meet the stringent desiderata set by him. But I show that (...) there are at least two synchronic rational constraints with distinctive and important, although only indirect, diachronic dimensions. Neither of them, however, supports the practical conservatism in the face of normative underdetermination that, according to Bratman, is part and parcel of the diachronic rationality of intention stability. (shrink)