How Can I run code hourly using JS?

Question

I did something like

setInterval(function() {
   console.log("!");
   }, 1000 * 60 * 60);

I want to run console.log every hour but the code doesn't work like what I want.

Let's say that I run the code at 1:30, then It would run console.log at 2:30. but What I want to do is run the code every hour. like 1:00, 2:00, 3:00.

Is there any way to do this? Thank you!

Possible duplicate of [JavaScript: How to do something every full hour?](http://stackoverflow.com/questions/12309019/javascript-how-to-do-something-every-full-hour) — Sebastian Simon, Jan 20 '17 at 06:28
use node-cron for this. http://stackoverflow.com/questions/20499225/i-need-a-nodejs-scheduler-that-allows-for-tasks-at-different-intervals — JSEvgeny, Jan 20 '17 at 06:33
@JavaEvgen I have only one question for you! I want to run something every 00:00AM, which is turning point of the day, Would this be work? `00 00 0 * * 0-6` — yolohoam, Jan 20 '17 at 07:02
try this one 0 0 0 * * *. Related to this post http://stackoverflow.com/questions/31138163/node-cron-run-every-midnight — JSEvgeny, Jan 20 '17 at 07:15

Robby Cornelissen · Answer 1 · 2017-01-20T06:46:07.027

This should do it:

let millisPerHour = 60 * 60 * 1000; // use 5 * 1000 (every 5 seconds) for testing
let millisPastTheHour = Date.now() % millisPerHour;
let millisToTheHour = millisPerHour - millisPastTheHour;

let fn = function() {
  console.log("Running at " + new Date());
}

setTimeout(function() {
  fn();
  
  setInterval(function() {
    fn();
  }, millisPerHour);
}, millisToTheHour);

I'm using a combination of setTimeout() and setInterval(). First I calculate the number of milliseconds until the next hour (millisToTheHour), then I use a timeout to execute the function and start an interval that will keep executing it every hour.

How Can I run code hourly using JS?

1 Answers1