Calendar plugin questions and help

Greetings,

I’m trying to wrap my head around the calendar plugin. Specifically creating an event. I noticed when I create an event it is posting it a month ahead than what it should be.

Sample data used and code:

...
let newDate = new Date(dp[0], dp[1], dp[2], tp[0], tp[1], 0, 0);
// Date data is 2017 09 22 13 00, which is September, but it's entering in October.
calendar.createEvent(eventName, eventLocation, eventNotes, startDate, endDate)
                .then(response => {
                    console.log('Success: ',response);
                }, err => {
                    console.log('Error: ', err );
                });

My next question is how is the modifyEvent method reliable? It goes off the content of the event and not an ID? What if someone changes the name of the event?

modifyEvent(title, location, notes, startDate, endDate, newTitle, newLocation, newNotes, newStartDate, newEndDate)

I did notice when I created an event I did get an ID back. Can I not store that to edit the event later or even check if that event exists so I do not add it again?