How to compare two times in javascript

Question

I'm struggling to compare two times.

I need to print Current class going based on the current time.

Example: current time based class going on the college/school

var now = new Date();
var TwentyFourHour = now.getHours();
var hour = now.getHours();
var min = now.getMinutes();
var mid = 'PM';

if (min < 10) {
    min = "0" + min;
}
if (hour > 12) {
    hour = hour - 12;
}
if (hour == 0) {
    hour = 12;
}
if (TwentyFourHour < 12) {
    mid = 'AM';
}
Current_time = hour + ':' + min + ':' + mid;

start_time = "09:00:PM";
end_time = "10:00:PM";



if (parseInt(start_time) <= parseInt(Current_time) || parseInt(end_time) >= parseInt(Current_time)) {

    console.log("C programming class is going");
} else {
    console.log("No class are avalible");
}

OUTPUT:
C programming class is going....

What is actually your specific question? What issues are you facing with your code? — B001ᛦ, Jun 27 '21 at 15:33
Based on the current time what class is going I want to show.... — Maseeha Tasneem, Jun 27 '21 at 15:35
_Based on the current time what class is going I want to show...._ Just a Repetition. What **issues** are you facing with your code? — B001ᛦ, Jun 27 '21 at 15:36
you moment js library, if you want to go with native date time calculation then please update question and write detailed instruction what issue you are facing and what output you expect — kamlesh parmar, Jun 27 '21 at 15:36
Does this answer your question? [Compare two dates with JavaScript](https://stackoverflow.com/questions/492994/compare-two-dates-with-javascript) — programmerRaj, Jun 27 '21 at 15:37
You're using `parseInt` to try and process *times*, not *ints*. And you wonder why it doesn't work...? — Niet the Dark Absol, Jun 27 '21 at 15:40

score 0 · Answer 1 · edited Jun 27 '21 at 15:46

It seems you are looking for the shortest path to have your homework done. Please check the references for Date function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/Date

Some tips:

Make sure you understand how the Date object is created. You can use strings!
If you want to define date manually using each day, month , value, you can!
Check your strings.. are you sure "09:00:PM" is a valid string for date?
Are you sure you can use parseInt for parsing dates?

Anyway, you need to do more research.

score 0 · Answer 2 · answered Jun 27 '21 at 16:06

The easiest way to check if a time is between a start and an end time is to store the time using unix time(https://en.wikipedia.org/wiki/Unix_time). It represents the time in seconds after 00:00:00 UTC on 1 January 1970. so you can do the following:

const startTime = 1624802400 // 27.6.21 16:00
const endTime = 1624809600 //27.6.21 18:00
const currentTime = Date.now()/1000

if(currentTime < endTime && currentTime > startTime){
    console.log('Class is going')
}
if(currentTime > endTime){
    console.log('Class ended')
}
if(currentTime < startTime){
    console.log('Class has not started')
}

Date.now() returns the current time in milliseconds so you need to divide it by 1000

What is the startTime and EndTime I can't able to understand.... — Maseeha Tasneem, Jun 27 '21 at 17:18

How to compare two times in javascript

2 Answers2