One way is to use year, month and day as parameters on new Date

new Date(year, month [, day [, hours [, minutes [, seconds [, milliseconds]]]]]);

You can prepare your date string by using a function.

Note: Month is 0-11, that is why m-1

Here is a snippet:

function prepareDate(d) {

  [d, m, y] = d.split(-); //Split the string

  return [y, m - 1, d]; //Return as an array with y,m,d sequence

}



let str = 25-12-2017;

let d = new Date(...prepareDate(str));



console.log(d.getTime());

Doc: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date