text: module.exports.valid_datetime = [
      '2018-11-11 12:34:56.1',
      '2018-11-11 12:34:56.12',
      '2018-11-11 12:34:56.123',
      '2018-11-11 12:34:56.1234',
      '2018-11-11 12:34:56',
      '2018/11/11 12:34:56',
      '2018.11.11 12:34:56',
      '2018.11.11T12:34:56Z',  // RFC3339
      '2018.11.11T12:34:56+09:00', // RFC3339
      '1999/1/1 00:00:00.000',
      '1999/01/01 0:0:0.000',
      '99/01/11 12:34:56.789',
      '99/01/01 00:00:00.000'
  ];
  
  module.exports.invalid_datetime = [
      undefined,
      '',
      '2018-11-11 30:11:11.123',
      '2018-11-11 11:61:11.123',
  //    '2018-11-11 11:11:71.123',  // not implement
      '2018-20-11 12:34:56.123',
      '2018-11-40 12:34:56.123',
      '2018-11-11 12:34',
      '2018-11-11',
      '12:34:56.123',
      '00:00:00.000',
      '99/01/ 12:34:56.789',
      '99//11 12:34:56.789',
      '10/11 12:34:56.789'
  ];
  