pragma solidity >=0.6.12;

// Author:	Louis Holbrook <dev@holbrook.no> 0826EDA1702D1E87C6E2875121D2E7BB88C2A746
// SPDX-License-Identifier:	AGPL-3.0-or-later
// File-version: 3

interface IExpire {
	// Contract has expired.
	event Expired(uint256 _timestamp);

	// Expiry time has changed.
	event ExpiryChange(uint256 indexed _oldTimestamp, uint256 _newTimestamp);

	// The current expiration timestamp.
	function expires() external returns (uint256);

	// Check expiry and apply expiration if expired.
	// Return values must be:
	// 0: not yet expired.
	// 1: already expired.
	// >1: expiry executed.
	function applyExpiry() external returns(uint8);
}