javascript add a day code example

Example 1: js date add 1 day

let date = new Date();
// add a day
date.setDate(date.getDate() + 1);

Example 2: javascript date add days

function addDays(originalDate, days){
  cloneDate = new Date(originalDate.valueOf());
  cloneDate.setDate(cloneDate.getDate() + days);
  return cloneDate;
}

let appointment = new Date("February 12, 2021 00:00:00");
let newAppointment = addDays(appointment, 7);

console.log(appointment.getDate()); // 12
console.log(newAppointment.getDate()); // 19

Example 3: javascript add days

Date.prototype.addDays = function(days) {
    var date = new Date(this.valueOf());
    date.setDate(date.getDate() + days);
    return date;
}