Date Add in Javascript (Tips & Trick)

Hi Guys, Good day to you ! allow me repost a programming tips that I copied from my another blog. enjoy !

---

I came across from a problem where I found a little difficulty using the existing Javascript standard date functions. especially when I need to 'add' the date forward or backward. let say, for example, I want to know what is the date one month after 'now', or what is the date 7 days from now ?

I'm so familiar with Coldfusion where it provide dateAdd() function where you can use to add a date with a certain unit of time. Unfortunately, there's none as easy as this in Javascript.

Therefore I created my own Javascript functions that works similar with it. here is the code.

 //Simple Date Add Function
      function dateAdd(datepart,number,objDate){
           y = objDate.getFullYear();
           m = objDate.getMonth()+1;
           d = objDate.getDate();
           hr =     objDate.getHours();
           mn =     objDate.getMinutes();
           sc =     objDate.getSeconds();
           newY=y;
           newM=m;
           newD=d;
           if (datepart== 'y'){
                newY = parseInt(y) + parseInt(number);
           } else if (datepart== 'm') {
                newM = parseInt(m) + parseInt(number);
           } else {
                newD = parseInt(d) + parseInt(number);
           }
           objNewDate = new Date(newY,newM,newD,hr,mn,sc);
           return objNewDate;
      }

This function took 3 parameters,

- Datepart. the option is "y" for year, "m" for month and "d" for day. currently this is the only options provided ^^, sure you can expand the usability on your own if you would so.


- Number. Number of units of datepart to add to date (positive, to get dates in the future; negative, to get dates in the past). Number must be an integer.


- objDate. Javascript Date/time object

Example :

function dateAddSample() {
	example1 = dateAdd("m",3,new Date()); //add current date 3 months forward
        example2 = dateAdd("m",-6,new Date()); //add current date 6 months backward
        example3 = dateAdd("d",7,new Date()); //add current date 7 days forward
        alert(example1);
        alert(example2);
        alert(example3);
}

That's all the code, hope it helpful. cheers !