sent date with timeSync is last month

[fits-fujiura-st]

Node Version: 12.20.0

Node BACstack Version: 0.2.4

• [ x ] Bug Report

Current Behaviour (Bug Report)

I sent time synchronization with current date, but a day of last month is sent.
Current date is April 13, 2021.

sample code:

const bacnet = require('node-bacnet');
const client = new bacnet();

client.timeSync(MY_DEVICE_IP, new Date());
// MY_DEVICE_IP is actually a valid IP

Expected Behaviour (Bug Report)

I expected timeSynchronization with "Date: April 13, 2021," is sent, but timeSynchronization with "Date: March 13, 2021," is sent

Suspicious code

In JavaScript, the getMonth() method returns the month from 0 to 11.
If library sends it as is, it means last month's data in the BACnet protocol.
So it need call getMonth() + 1 to create buffer in encodeBacnetDate.

code to be fixed:

node-bacstack/lib/asn1.js

Line 322 in 5e22199

buffer.buffer[buffer.offset++] = value.getMonth();

[Apollon77]

@fits-fujiura could you provide this as a PR?

[fits-fujiura-st]

@Apollon77

@fits-fujiura could you provide this as a PR?

Yes, I can.
First, I will check CONTRIBUTING.md.