How to get last month date in JavaScript or jquery

Question

I am trying to get specific date in java script.

What I am trying to do is. I have variable called frequency Which can be Daily , Weekly and Monthly

if(frequency=="daily")
{
    date='current_date -2 days';
}
    else if ( frequency== 'weekly')
{
    date='current_date -8 days';
}
    else if ( frequency == 'monthly')
{
    date='current_date -32 days';
}

This is the way I get current date with required format.

var today = new Date();
var dd = today.getDate();
var mm = today.getMonth()+1; //January is 0!
var yyyy = today.getFullYear();
var hh = today.getHours();
var min = today.getMinutes();
var ss = today.getSeconds();

if(dd<10) {
    dd='0'+dd
} 

if(mm<10) {
    mm='0'+mm
} 

//  today = mm+'/'+dd+'/'+yyyy;

today = yyyy + "-" + mm + "-" + dd + " " + hh + ":" + mm + ":" + ss ;
alert("Today's date :"+today);

But, I am facing problem in subtracting the days

can anyone give an idea how can I achieve this.

Answer 1

You can simply do this:

function setDate(frequency) {
  var today = new Date(),
    date;
  if (frequency == "daily") {
    date = today.getTime() - (2*24*60*60*1000); // 2 days 24 hrs 60 mins 60 secs 1000 ms
  } else if (frequency == 'weekly') {
    date = today.getTime() - (8*24*60*60*1000);
  } else if (frequency == 'monthly') {
    date = today.getTime() - (32*24*60*60*1000);
  }
  return new Date(date);
}

document.querySelector('pre').innerHTML = setDate('monthly');

<pre></pre>

You need to convert days into time in ms miliseconds to convert it in time then you can subtract it from current time in ms after it you can return it as a new Date(date);.