TradersToken_TRC20.sol

pragma solidity ^0.4.25;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

contract TRC20 {
    using SafeMath for uint256;
    // Public variables of the token
    string public name;
    string public symbol;
    uint8 public decimals = 6;
    uint256 public totalSupply;

    // This creates an array with all balances
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    // This generates a public event on the blockchain that will notify clients
    event Transfer(address indexed from, address indexed to, uint256 value);

    // This generates a public event on the blockchain that will notify clients
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value);

    /**
     * Constructor function
     *
     * Initializes contract with initial supply tokens to the creator of the contract
     */
    uint256 initialSupply = 250000000000;
    string tokenName = 'Traders Token';
    string tokenSymbol = 'TRDST';
    address public owner;
    address public wallet = 0x73F8682006eE9899DfF82121Fb7b21c5dB4f5A5c;

    uint public endDate2021 = 1633026600;
    uint public endDate2022 = 1664562600;
    uint public endDate2023 = 1696098600;
    uint public endDate2024 = 1727721000;
    uint public endDate2025 = 1759257000;
    
    constructor() public {

        totalSupply = initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
        balanceOf[wallet] = 50000000000* 10 ** uint256(decimals);                // Give the creator all initial tokens
        name = tokenName;                                   // Set the name for display purposes
        symbol = tokenSymbol;                               // Set the symbol for display purposes
        owner=msg.sender;
    }

    modifier ownerOnly(){
        require(msg.sender==owner || msg.sender==wallet);
        _;
    }

    /**
     * Internal transfer, only can be called by this contract
     */
    function _transfer(address _from, address _to, uint _value) internal {
        // Prevent transfer to 0x0 address. Use burn() instead
        require(_to != 0x0);
        // Check if the sender has enough
        require(balanceOf[_from] >= _value);
        // Check for overflows
        require(balanceOf[_to] + _value >= balanceOf[_to]);
        // Save this for an assertion in the future
        uint previousBalances = balanceOf[_from] + balanceOf[_to];
        // Subtract from the sender
        balanceOf[_from] -= _value;
        // Add the same to the recipient
        balanceOf[_to] += _value;
        emit Transfer(_from, _to, _value);
        // Asserts are used to use static analysis to find bugs in your code. They should never fail
        assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
    }

    /**
     * Transfer tokens
     *
     * Send `_value` tokens to `_to` from your account
     *
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transfer(address _to, uint256 _value) public returns (bool success) {
        _transfer(msg.sender, _to, _value);
        return true;
    }

    /**
     * Transfer tokens from other address
     *
     * Send `_value` tokens to `_to` on behalf of `_from`
     *
     * @param _from The address of the sender
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(_value <= allowance[_from][msg.sender]);     // Check allowance
        allowance[_from][msg.sender] -= _value;
        _transfer(_from, _to, _value);
        return true;
    }

    /**
     * Set allowance for other address
     *
     * Allows `_spender` to spend no more than `_value` tokens on your behalf
     *
     * @param _spender The address authorized to spend
     * @param _value the max amount they can spend
     */
    function approve(address _spender, uint256 _value) public
    returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }

    /**
     * Destroy tokens
     *
     * Remove `_value` tokens from the system irreversibly
     *
     * @param _value the amount of money to burn
     */
    function burn(uint256 _value) public returns (bool success) {
        require(balanceOf[msg.sender] >= _value);   // Check if the sender has enough
        balanceOf[msg.sender] -= _value;            // Subtract from the sender
        totalSupply -= _value;                      // Updates totalSupply
        emit Burn(msg.sender, _value);
        return true;
    }

    /**
     * Destroy tokens from other account
     *
     * Remove `_value` tokens from the system irreversibly on behalf of `_from`.
     *
     * @param _from the address of the sender
     * @param _value the amount of money to burn
     */
    function burnFrom(address _from, uint256 _value) public returns (bool success) {
        require(balanceOf[_from] >= _value);                // Check if the targeted balance is enough
        require(_value <= allowance[_from][msg.sender]);    // Check allowance
        balanceOf[_from] -= _value;                         // Subtract from the targeted balance
        allowance[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
        totalSupply -= _value;                              // Update totalSupply
        emit Burn(_from, _value);
        return true;
    }

    function _mint(address account, uint256 value) internal {
        require(account != address(0));

        totalSupply += value;
        balanceOf[account] += value;
        emit Transfer(address(0), account, value);
    }

    function transferOwnership(address newOwner) ownerOnly external{
        if (newOwner != address(0)) {
          owner = newOwner;
        }
    }    
    
    function release2021() ownerOnly external returns(bool success){
        if(now>endDate2021){
            balanceOf[wallet] += 25000000000 * 10 ** uint256(decimals);
            return true;
        }
        else
            return false;
    }

    function release2022() ownerOnly external returns(bool success){
        if(now>endDate2022){
            balanceOf[wallet] += 50000000000 * 10 ** uint256(decimals);
            return true;
        }
        else
            return false;
    }

    function release2023() ownerOnly external returns(bool success){
        if(now>endDate2023){
            balanceOf[wallet] += 50000000000 * 10 ** uint256(decimals);
            return true;
        }
        else
            return false;
    }

    function release2024() ownerOnly external returns(bool success){
        if(now>endDate2024){
            balanceOf[wallet] += 50000000000* 10 ** uint256(decimals);
            return true;
        }
        else
            return false;
    }
    
    function release2025() ownerOnly external returns(bool success){
        if(now>endDate2025){
            balanceOf[wallet] += 25000000000* 10 ** uint256(decimals);
            return true;
        }
        else
            return false;
    }


}