Comparing date in frappe or js

I want to check given date1 is Today or not
I used 

var date2 =get_today();
var result = (date1 == date2); 

It works successfully.


After that, I want to check, given date1 is Today or Yesterday or The day before yesterday. I used <= operator, but its not working properly.
After searching I come up with this solution, before comparing date we need to parse it.
Solution is:

var a = Date.parse(dataContext.ETD);

var b =  Date.parse(get_today());

var d = (a - b)/(1000 * 3600 * 24);

var c = ((d==0)||(d==(-1))||(d==(-2))); //returns true if ETD is today, yesterday or the day before yesterday

 

Please write comment if you have any doubt or suggestion.