iloveyii / day_diff

Find difference between two using Java Script without using any build Date function

Date Difference

• Please write a program using JavaScript that can calculate the number of days in-between two given dates.
• You are not allowed to use any built in date/time/calendar functionality.

Run

• Git clone the repository git clone https://github.com/iloveyii/day_diff.git
• CD to directory and install dependencies npm i
• Run the app npm start
• Make changes to run.js and see results

How to use in code

• Create two object s

var oDate = require("./index");
//                    year month day hour minute
var date1 = new oDate(1960, 1, 1, 0, 0);
var date2 = new oDate(2021, 5, 21, 0, 0);

• And then call the function getDaysDiff as below

console.log("Number of days:", date2.getDaysDiff(date1);
// prints 22421

How it works?

• Generally Datetime is first converted to GMT and then Unix timestamp (number of seconds elapsed since 1-1-1970)
• We convert the dates to timestamp (since REFERENCE_YEAR: 1, 1900, 1970)
• If we set REFERENCE_YEAR to 1970 then dates after this year would be calculated correctly, therefore the smaller its value the better
• The absolute difference between the timestamps of the two dates are then divided by 86400 (sec) to get the number days

Limitations

• The function cannot calculate dates older than 1
• The timezones are not implemented and you should add/subtract hours while creating object of oDate