While also using the international geologic time scale, many nations–especially those with isolated and therefore non-standard prehistories–use their own systems of dividing geologic time into epochs and faunal stages. In New Zealand, these epochs and stages use local place names (mainly Māori in origin) back to the Permian. Although the New Zealand geologic time scale has not been formally adopted, it has been widely used by earth scientists, geologists and palaeontologists in New Zealand since J. S. Crampton proposed it in 1995. The most recent calibrated update was in 2015.