How do I get the time of day in javascript/Node.js?

This function will return you the date and time in the following format: YYYY:MM:DD:HH:MM:SS. It also works in Node.js.

function getDateTime() {

    var date = new Date();

    var hour = date.getHours();
    hour = (hour < 10 ? "0" : "") + hour;

    var min  = date.getMinutes();
    min = (min < 10 ? "0" : "") + min;

    var sec  = date.getSeconds();
    sec = (sec < 10 ? "0" : "") + sec;

    var year = date.getFullYear();

    var month = date.getMonth() + 1;
    month = (month < 10 ? "0" : "") + month;

    var day  = date.getDate();
    day = (day < 10 ? "0" : "") + day;

    return year + ":" + month + ":" + day + ":" + hour + ":" + min + ":" + sec;

}

You should checkout the Date object.

In particular, you can look at the getHours() method for the Date object.

getHours() return the time from 0 - 23, so make sure to deal with it accordingly. I think 0-23 is a bit more intuitive since military time runs from 0 - 23, but it's up to you.

With that in mind, the code would be something along the lines of:

var date = new Date();
var current_hour = date.getHours();

Check out the moment.js library. It works with browsers as well as with Node.JS. Allows you to write

moment().hour();

or

moment().hours();

without prior writing of any functions.

Both prior answers are definitely good solutions. If you're amenable to a library, I like moment.js - it does a lot more than just getting/formatting the date.