NodeJS - perform an activity between a specific start and end time

cron_script.sh

# set your crontab cron like this, to check after every 5 minutes let's say
*/5 * * * * /home/ub/local/bin/node /mnt/d/tmp/cron001/cron.js >> /mnt/d/tmp/cron001/activtyOn21-5.log

# for every minute 
#* * * * * /home/ub/local/bin/node /mnt/d/tmp/cron001/cron.js >> /mnt/d/tmp/cron001/activtyOn21-5.log

time_based_activity.js

var fs = require('fs');

var dateTimeToStartActivityString = 'Sat May 20 2017 17:38:00.00 GMT+0500';
var dateTimeToStopActivityString = 'Sat May 20 2017 17:39:00.00 GMT+0500';

var dateTimeToStartActivity = new Date(dateTimeToStartActivityString);
var dateTimeToStopActivity = new Date(dateTimeToStopActivityString);

var start_activity_lock_file = 'start_activity.lock';

var currentDateTime = new Date();

function startActivity() {
  console.log('difference > 0 time to stop');
  console.log('stopping site');
}

function startActivityInternal() {
  if (!fs.existsSync(start_activity_lock_file)) {
    startActivity();
    fs.closeSync(fs.openSync(start_activity_lock_file, 'w'));
    console.log('lock file created');
  } else {
    console.log('site was down when required');
  }
}

function stopActivity() {
  console.log('make the site up again');
}

function main() {
	var difference = currentDateTime - dateTimeToStartActivity; // difference in milliseconds

	console.log('dateTimeToStartActivity', dateTimeToStartActivity);
	console.log('currentDateTime', currentDateTime);
	console.log('difference = ', difference);

	if (difference > 0) {
		startActivityInternal();
	} else {
		console.log('difference < 0 ' + (difference / 1000) + ' seconds remaining before starting task');
	}

	var newDiff = currentDateTime - dateTimeToStopActivity;

	if (currentDateTime > dateTimeToStopActivity) {
		stopActivity();
	} else {
		console.log('newDiff ' + (newDiff / 1000) + ' seconds remaining before we make the site up again');
	}
}

main();