If Date is Less Than Current Date by 15mins then do something

Question

I have been trying to work on something with dates and I was wondering how to check if it is less than 30mins or 15mins difference then should call a function.

let btnCheck = document.querySelector('button');
let result = document.querySeletor('h1');

let current = new Date();
let date = new Date('01/01/2021');

btnCheck.addEventListener('click', () => {
let ms1 = current.getTime();
let ms2 = date.getTime();

result.innerText = ms2 < ms1;
});

So far it results in a true or false but I wanted to add something if the current date is less than the date by 15mis or 30 mins show a button.

Update: Using Moment Library it can be possible through something like this: https://momentjs.com/docs/#/displaying/difference/ But I'm only going to use this for a one-time function.

Thank you in advance! Much appreciated!

I'm more about learning how to do it in pure js. I have checked that moment has 'durations'. It would probably be easy if a subtract the date from the current date and then compare it. I still don't know how to do that. In theory, It sounds easy in my head. Thanks though! — CTRL-In-Knowledge, Dec 16 '21 at 17:00
For everyone who suggests installing moment (not only Vasyl), – please, read [this article from the moment's docs](https://momentjs.com/docs/#/-project-status/). Also, installing a gigantic library to use just one little function that can be easily implemented is a bit much. — Parzh from Ukraine, Dec 16 '21 at 17:19
There are many questions and answers about getting the [difference between to dates](https://stackoverflow.com/search?q=%5Bjavascript%5D+difference+between+dates) already. — RobG, Dec 16 '21 at 20:18

score 0 · Answer 1 · answered Dec 16 '21 at 17:11

As Vasyl already said you can use the moment library for this.

If you really want to use pure javascript the documentation of the Date object in JS is pretty good. Take a look here. You have to take into account that the difference is given in milliseconds, thus the calculations. Based on the documentation example i would do it like so (You are free to refactor!):

let btnCheck = document.querySelector('button');
let result = document.querySelector('h1');

let current = new Date();
let date = new Date('01/01/2021');

btnCheck.addEventListener('click', () => {
  let ms1 = current.getTime();
  let ms2 = date.getTime();

  //This checks if the difference is less than 15 minutes
  if((ms1 - ms2) / 1000 / 60 < 15 ){
  };

  //This checks if the difference is less than 30 minutes
  if((ms1 - ms2) / 1000 / 60 < 30 ){
  };
});

Sankhnad Mishra · Answer 2 · 2021-12-16T17:30:43.023

0

You can do something like this -

const btnCheck = document.querySelector('button');
const result = document.querySeletor('h1');

let current = new Date('2011/10/09 12:00');
let date = new Date('2011/10/09 11:30');

btnCheck.addEventListener('click', () => {
    const diff = Math.abs(current - date);
    if (diff === 15 || diff === 30) { // if (diff <= 30) { 
        result.innerText = diff;
        btnCheck.disabled = false;
    }else{
        btnCheck.disabled = true;
    }
});

edited Dec 16 '21 at 17:30

answered Dec 16 '21 at 17:23

Sankhnad Mishra

110
1
12

Creating Dates from unsupported string formats is not a good idea, see [*Why does Date.parse give incorrect results?*](https://stackoverflow.com/questions/2587345/why-does-date-parse-give-incorrect-results) This tests whether the difference between the dates is exactly 15 ms or 30 ms, it doesn't test for minutes. – RobG Dec 16 '21 at 20:11

If Date is Less Than Current Date by 15mins then do something

2 Answers2