NodeJs server side is not starting due of function import - node.js

Question

Firs time I faced with such issue, I have (the working case):
const weekendsInMonth = (anydate) => {
let today_tmp = new Date();
let today = new Date(today_tmp.getTime() - today_tmp.getTimezoneOffset()*60*1000);
let lastDayOfMonth = new Date(today.getFullYear(), today.getMonth()+1, 0).getDate();
let myDate = today;
//some other function code
Once I do modification to function (only anydate IN variable, second row):
const weekendsInMonth = (anydate) => {
let today_tmp = new Date(anydate);
let today = new Date(today_tmp.getTime() - today_tmp.getTimezoneOffset()*60*1000);
let lastDayOfMonth = new Date(today.getFullYear(), today.getMonth()+1, 0).getDate();
let myDate = today;
//some other function code
The NodeJs says only:
[nodemon] restarting due to changes...
[nodemon] starting `node server.js`
And nothing happens, actually there is more rows in output should come, like web server started at port, etc. No warnings, no erros and app page could not be viewev in browser (only error - ERR_CONNECTION_REFUSED). What am I doing wrong?
I am importing this function to my server.js as:
const {daysInThisMonth, weekendsInMonth, } = require("./src/core/functions");
Same time the other similar function does not fault:
const daysInThisMonth = (date) => {
var now = new Date(date);
return new Date(now.getFullYear(), now.getMonth()+1, 0).getDate();
}

Answer 1

I figured out it. The problem was that date must be defined in this case:
const weekendsInMonth = (anydate = new Date) => {
let today_tmp = new Date();
let today = new Date(today_tmp.getTime() - today_tmp.getTimezoneOffset()*60*1000);
let lastDayOfMonth = new Date(today.getFullYear(), today.getMonth()+1, 0).getDate();
let myDate = today;
//some other function code
For me this case was a surprise. Due this function only calling inside another function in a special circumstance. After I did a debug and this function is asking for date to be defined first.