HTML:

<input id="appt-time" type="time" name="appt-time" value="13:30">

JS

const timeFrom12hto24h = time12h => {
  const [time, meridiem] = time12h.split(" ");
  let [hours, minutes] = time.split(":");
  if (hours === "12") hours = "00";
  if (meridiem === "PM") hours = parseInt(hours, 10) + 12;
  return {hours, minutes}
};

const getMyObjectTime= timeFrom12hto24h('12:00 PM');

// apply the time to the HTML element
document.getElementById("appt-time").value = getMyObjectTime.hours + ':' + getMyObjectTime.minutes;

// one way to generate the needed time object
const dateInMiliseconds = new Date().setHours(getMyObjectTime.hours, getMyObjectTime.minutes, 0)
console.log(dateInMiliseconds);

In case there is moment.js already used in the project it would be like this:

HTML:

<input id="appt-time" type="time" name="appt-time" value="13:30">

JS:

// apply the time to the HTML element
document.getElementById("appt-time").value = moment("01:00 PM", 'hh:mm A').format('HH:mm')

// one way to generate the needed time object
let [hour, minutes] =  moment("01:00 PM", 'hh:mm A').format('HH,mm').split(',');
const dateInMiliseconds = new Date().setHours(hour,minutes, 0)
console.log(dateInMiliseconds);

Ive been able to create a function that can do the conversion, since I did not find any solution to this.

const dateFromTime = ({ timeString }) => {
    const dateTime = new Date();
    let timeHours = parseInt(timeString.substring(0, 2));
    let timeMinutes = parseInt(timeString.substring(3, 5));
    let timeAMPM = timeString.substring(6,
    if (timeAMPM === "PM") {
        timeHours += 12;

    dateTime.setHours( timeHours, timeMinutes, 0, 0);
    return dateTime;
}
const dateTime = dateFromTime({ timeString: "12:00 PM" });

This get the current date and time and instead sets the time to the specified time. and returns that

For any improvements, please suggest the right way to do this.

You just need to give the correct format to the Date object.

solution 1

If you don't care about date then you can simply convert like this.

let startTime = new Date(`2022/01/01 12:00 PM`);

solution 2

If you need today's date then you can simply convert like this.

let startTime = new Date(`${new Date().toDateString()} 12:00 PM`)