Javscript Small savings calculator

01 January 2020 — Written by Mitesh Patel

The script is created purely based the video I saw on youtube about Personal finance on how to save money with small savings.

If you invest 2 INR a day,In a year you can save around 133590 INR.

The calculation goes like: if on the, 1st of january you save 2 rupees 2nd january you have to save 22 = 4 and 3 day 23 = 6 and likewise.

You can not ideally transac this small amount to the bank, so I created this script to calculate monthly savings, so you can put that amount aside for any given month.

	/**
	* The script is created purely based the video I saw on youtube about
	* Personal finance on how to save money with small savings.
	*
	* If you invest 2 INR a day,In a year you can save around 133590 INR.
	*
	* The calculation goes like if on the 1st of january you save 2 rupees
	* 2nd january you have to save 22 = 4 and 3 day 23 = 6 and likewise.
	*
	* You can not ideally transac this small amount to the bank, so I created
	* this script to calculate monthly savings, so you can put that amount aside
	* for any given month.
	*/

	/**
	* Amount to pay on any given day.
	*
	* This will give you the money that you have to save on the 70th day of the
	* year and it will return the today's saving and total saving till the given
	* day
	*
	* @param {*} day
	* @param {*} dailyInvest
	*/
	function amountToPay(day, dailyInvest = 2) {
	let currentInvest = 0;
	let amount = 0;
	for (let i = 1; i <= day; i++) {
	currentInvest = i * dailyInvest;
	amount = amount + currentInvest;
	}
	return {
	today: currentInvest,
	total: amount
	};
	}

	/**
	* Amount to pay in a month.
	*
	* Pass the month and a year and this will given you how money you
	* Need to invest for the given month.
	*
	* @param {*} month
	* @param {*} year
	*/
	function amountToPayInMonth(month, year) {
	const { firstDay, lastDay } = daysNumberOfMonth(month, year);
	const { total: firstDayPay } = amountToPay(getDayOfTheYear(firstDay));
	const { total: lastDayPay } = amountToPay(getDayOfTheYear(lastDay));
	// console.log(firstDayPay);
	return lastDayPay - firstDayPay;
	}

	/**
	* First and last day of the month.
	*
	* @param {*} month
	* @param {*} year
	*/
	function daysNumberOfMonth(month, year) {
	var date = new Date(year + "-" + month + "-01");
	var firstDay = new Date(date.getFullYear(), date.getMonth(), 1);
	var lastDay = new Date(date.getFullYear(), date.getMonth() + 1, 0);
	return {
	firstDay: firstDay,
	lastDay: lastDay
	};
	}

	/**
	* Get the number of day of the given date.
	*
	* returns the number of the day in a year, if you want to know
	* what's the day in year is 29th of august. it accepts the date
	* object or array [year, month, day].
	*
	* @param {*} dateobj
	* Date object or array [year, month, day].
	*/
	function getDayOfTheYear(dateobj) {
	const currentdate = Array.isArray(dateobj)
	? new Date(dateobj.join("-"))
	: dateobj;

	const timestmp = new Date().setFullYear(new Date().getFullYear(), 0, 1);
	const yearFirstDay = Math.floor(timestmp / 86400000);
	const today = Math.ceil(currentdate.getTime() / 86400000);
	const dayOfYear = today - yearFirstDay;
	return dayOfYear + 1;
	}


	/**
	* Total saving in year.
	*/
	let totalpay = 0;
	for (let i = 1; i <= 12; i++) {
	const currentPay = amountToPayInMonth(i, "2020");
	totalpay = totalpay + currentPay;
	}
	// const pay = amountToPayInMonth("01", "2020");
	console.log(totalpay);
	// console.log(getDayOfTheYear(month.lastDay));
	console.log(amountToPay(365));

view raw savings_func.js hosted with ❤ by GitHub