JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>
        today - 10 days
    </li>
    <li>
        <input type="date" id="dt10days">
    </li>
    <li>
        today + 2 days
    </li>
    <li>
        <input type="date" id="dt2days">
    </li>
        
    <li>
        today + 3 weeks
    </li> 
    <li>
        <input type="date" id="dt3weeks">
    </li>
        
    <li>
        today + 7 months
    </li> 
    <li>
        <input type="date" id="dt7months">
    </li>
        
    <li>
        today + 4 years
    </li> 
    <li>
        <input type="date" id="dt4years">
    </li>
</ul>

CSS

ul li {
    list-style: none;    
}

JavaScript

Date.prototype.addSeconds = function(seconds) {
    this.setSeconds(this.getSeconds() + seconds);
    return this;
};

Date.prototype.addMinutes = function(minutes) {
    this.setMinutes(this.getMinutes() + minutes);
    return this;
};

Date.prototype.addHours = function(hours) {
    this.setHours(this.getHours() + hours);
    return this;
};

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

Date.prototype.addWeeks = function(weeks) {
    this.addDays(weeks*7);
    return this;
};

Date.prototype.addMonths = function (months) {
    var dt = this.getDate();
    
    this.setMonth(this.getMonth() + months);
    var currDt = this.getDate();
    
    if (dt !== currDt) {  
        this.addDays(-currDt);
    }
    
    return this;
};

Date.prototype.addYears = function(years) {
    var dt = this.getDate();
    
    this.setFullYear(this.getFullYear() + years);
    
    var currDt = this.getDate();
    
    if (dt !== currDt) {  
        this.addDays(-currDt);
    }
    
    return this;
};

$(document).ready(function() {
    var now = new Date();
    now.addDays(-10);
    $("#dt10days")[0].valueAsDate = now;   
    
    var now = new Date();
    now.addDays(2);
    $("#dt2days")[0].valueAsDate = now;   
    
    now = new Date();
    now.addWeeks(3);
    $("#dt3weeks")[0].valueAsDate = now;
    
    now = new Date();
    now.addMonths(7);
    $("#dt7months")[0].valueAsDate = now;  
    
    now = new Date();
    now.addYears(4);
    $("#dt4years")[0].valueAsDate = now;
});