How to compare time in javascript?

Question

I have two time in the format "HH:MM" i want to compare them i have the following code to get the time of now in my format:

current_time = new Date();
hour = current_time.getHours();
minute = current_time.getMinutes();
if(hour<10){hour='0'+hour} if(minute<10){minute='0'+minute}
my_time = hour+':'+minute;

And this code is to get the time after subtracting the GMT difference :

d = new Date()
var n = d.getTimezoneOffset();
var n1 = Math.abs(n);
var difference = (n1/60); 
my_time = my_time - (0+difference);

Now the value of my_time should be compared with the value of match_time:

match_time = 10:00;//for example
if(my_time > match_time)
{
  alert('yes');
}
else
{
  alert('No');
}

how can I compare those values as time when they are a string ???

Answer 1

use Date objects. Date.setHours() allows you to specify hour, minutes, seconds

var currentD = new Date();
var startHappyHourD = new Date();
startHappyHourD.setHours(17,30,0); // 5.30 pm
var endHappyHourD = new Date();
endHappyHourD.setHours(18,30,0); // 6.30 pm

console.log("happy hour?")
if(currentD >= startHappyHourD && currentD < endHappyHourD ){
    console.log("yes!");
}else{
    console.log("no, sorry! between 5.30pm and 6.30pm");
}

Answer 2

Assuming you are not interested in time zones and only need to compare two formatted time strings in 24h time format, you can just compare strings.

let time1 = '09:12';
let time2 = '12:22';

if (time1 > time2) {
 alert('yes')
} else {
 alert('no')
}

It works because strings in JS are compared symbol by symbol. So when compared '09:12' > '12:22' JS first checks if '0' == '1' and if false '0' > '1', and then returns result.

For comparison of strings '01' > '02', it will check if '0' == '0' then skip to next symbol in both strings and compare '1' > '2' which is false.

Strings has to be normalized to hh:mm, otherwise you will get unexpected results like:

"9:12" > "12:22" //true

Answer 3

Date.parse('25/09/2013 13:31') > Date.parse('25/09/2013 9:15')

EDIT:

Note that you are parsing an arbitrary date that you're not interested in, it just needs to be the same on both sides.