Problem with code

Question

There is problem that my code shows the month of November not December
https://code.sololearn.com/W5825qK13Kcj/?ref=app

Answer 1

The `getMonth` method of a Date object returns a zero based value indicating the month. That is, 0 for January, 1 for February, and so on.

To get passed it, just add one to <mon> variable value

var mon = d.getMonth() + 1;

https://www.w3schools.com/jsref/jsref_getmonth.asp