Parsing dates is a pain in JavaScript as there's no extensive native support. However you could do something like the following by relying on the Date(year, month, day [, hour, minute, second, millisecond]) constructor signature of the Date object.

var dateString = '17-09-2013 10:08',
    dateTimeParts = dateString.split(' '),
    timeParts = dateTimeParts[1].split(':'),
    dateParts = dateTimeParts[0].split('-'),
    date;

date = new Date(dateParts[2], parseInt(dateParts[1], 10) - 1, dateParts[0], timeParts[0], timeParts[1]);

console.log(date.getTime()); //1379426880000
console.log(date); //Tue Sep 17 2013 10:08:00 GMT-0400

You could also use a regular expression with capturing groups to parse the date string in one line.

var dateParts = '17-09-2013 10:08'.match(/(\d+)-(\d+)-(\d+) (\d+):(\d+)/);

console.log(dateParts); // ["17-09-2013 10:08", "17", "09", "2013", "10", "08"]

You can initialise a Date object and call getTime() to get it in unix form. It comes out in milliseconds so you'll need to divide by 1000 to get it in seconds.

(new Date("2013/09/05 15:34:00").getTime()/1000)

It may have decimal bits so wrapping it in Math.round would clean that.

Math.round(new Date("2013/09/05 15:34:00").getTime()/1000)

let unix_timestamp = 1549312452;

// Create a new JavaScript Date object based on the timestamp
// multiplied by 1000 so that the argument is in milliseconds, not seconds
var date = new Date(unix_timestamp * 1000);

// Hours part from the timestamp
var hours = date.getHours();

// Minutes part from the timestamp
var minutes = "0" + date.getMinutes();

// Seconds part from the timestamp
var seconds = "0" + date.getSeconds();

// Will display time in 10:30:23 format
var formattedTime = hours + ':' + minutes.substr(-2) + ':' + seconds.substr(-2);

console.log(formattedTime);

For more information regarding the Date object, please refer to MDN or the ECMAScript 5 specification.

Just create a Date object from it and do .getTime() or use Date.parse():

var d = new Date("Wed Jun 20 19:20:44 +0000 2012");
d.getTime(); //returns 1340220044000

//OR

Date.parse("Wed Jun 20 19:20:44 +0000 2012"); //returns 1340220044000

Works great if your "human time" string is in a format that the Date constructor understands (which the example you posted is).

EDIT

Realized you may mean a Unix timestamp, which is seconds passed since the epoch (not ms like JS timestamps). In that case simply divide the JS timestamp by 1000:

//if you want to truncate ms instead of rounding just use Math.floor()
Math.round(Date.parse("Wed Jun 20 19:20:44 +0000 2012") / 1000); //returns 1340220044

Split the string into its parts and provide them directly to the Date constructor:

Update:

var myDate = "26-02-2012";
myDate = myDate.split("-");
var newDate = new Date( myDate[2], myDate[1] - 1, myDate[0]);
console.log(newDate.getTime());

Updated: Also, you can use a regular expression to split the string, for example:

const dtStr = "26/02/2012";
const [d, m, y] = dtStr.split(/-|\//); // splits "26-02-2012" or "26/02/2012"
const date = new Date(y, m - 1, d);
console.log(date.getTime());