How to round to nearest hour using JavaScript Date Object

Question

I am working on a project that requires a time in the future to be set using the Date object.

For example:

futureTime = new Date();
futureTime.setHours(futureTime.getHours()+2);

My questions is; once the future date is set, how can I round to the closest full hour and then set the futureTime var with it?

For example:

Given 8:55 => var futureTime = 9:00
Given 16:23 => var futureTime = 16:00

Any help would be appreciated!

question from:https://stackoverflow.com/questions/7293306/how-to-round-to-nearest-hour-using-javascript-date-object

Answer 1

Round the minutes and then clear the minutes:

var date = new Date(2011,1,1,4,55); // 4:55
roundMinutes(date); // 5:00

function roundMinutes(date) {

    date.setHours(date.getHours() + Math.round(date.getMinutes()/60));
    date.setMinutes(0, 0, 0); // Resets also seconds and milliseconds

    return date;
}