two different hours subtraction Angular 6 - angular6

Question

I am trying to do how to subtract two different hours that is captured:
Here is TS code
clockingIn() {
var dt = new Date()
this.clockedIn= new Date().getHours()+':'+ new Date().getMinutes()+':'+ new Date().getSeconds();
console.log('clockin', this.clockedIn);
this.disableClockIn = true;
this.disableClockOut = false;
}
clockingOut() {
var dt2 = new Date();
this.clockedOut= new Date().getHours()+':'+ new Date().getMinutes()+':'+ new Date().getSeconds();
console.log('clockout', this.clockedOut);
this.disableClockIn = false;
this.disableClockOut = true;
}
subtraction() {
var now = "04/09/2013 15:00:00";
var then = "02/09/2013 14:20:30";
var ms = moment(now,"DD/MM/YYYY HH:mm:ss").diff(moment(then,"DD/MM/YYYY HH:mm:ss"));
var d = moment.duration(ms);
}
//table
test() {
const data = {
dateClock: this.dateobj(),
Job: this.selectedJob,
clockI: this.clockedIn,
clockO: this.clockedOut,
Hoursworked: this.subtraction()
};
this.dataSource.data.push(data);
this.refresh();
console.log(this.dataSource);
}
So this is a clock in and Clock out.
I want these two can calculate (Clock Out - Clock In) to see the difference of two hours in the table that I made. So this way, I can see the diff time between Clock Out and Clock In.

Answer 1

I am assuming your duration will be calculated in subtraction function.
Below changes will get the result :
subtraction() {
var now = "04/09/2013 15:00:00";
var then = "02/09/2013 14:20:30";
// I have set to minutes. Change unit as per your requirement by
// referring doc given as reference
var unit = 'm';
return moment(now,"DD/MM/YYYY HH:mm:ss").diff(moment(then,"DD/MM/YYYY HH:mm:ss"), unit);
}
Moment.js duration