ICron.sol

pragma solidity ^0.4.25;
contract ICron { 
 function initTimestamp() public view returns (uint256);
 Return the number of occurrences of the stored crontab expression from initTimestamp() to a given _timestamp
 // Number of current epoch (number of periods) since the Smart Contract was deployed
 function height() public view returns (uint256);
 // Epoch of a predefined timestamp
 function heightOf(uint256 _timestamp) public view returns (uint256);
 //Return the next timestamp where height will be changed, 2^256-1 if no new event is expected
 function next) public view returns (uint256);

}