function getCronString(interval, value, callback) {
    switch (interval) {
      case 'monthly': {
        callback(`***/${value}**`);
      }
      case 'weekly': {
        const days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
        days.forEach(function(day, index) {
          if (day === value) {
            console.log('day-->>', index);
            callback(`*****/${days}`);
          }
        });
      }
      case 'daily': {
        callback(`**/${value}***`);
      }
    }
  }

getCronString(1000, (value) => {
  console.log(value)
})