//npm i --save cron-parser
var parser = require('cron-parser');

try {
    var interval = parser.parseExpression('0 0 15 * * * *');

    console.log('Date: ', interval.next().toString()); // Sat Dec 29 2012 00:42:00 GMT+0200 (EET)
    console.log('Date: ', interval.next().toString()); // Sat Dec 29 2012 00:44:00 GMT+0200 (EET)

    console.log('Date: ', interval.next().toString()); // Sat Dec 29 2012 00:42:00 GMT+0200 (EET)
    console.log('Date: ', interval.next().toString()); // Sat Dec 29 2012 00:40:00 GMT+0200 (EET)
} catch (err) {
    console.log('Error: ' + err.message);
}