Call function now and every 1 minute on full minute?

Question

Using timer I am able to call a function every 1 minute but not the way I want, if now is 10:35:21 the function should be called like this:

at 10:35:21
at 10:36:00
at 10:37:00
at 10:38:00
at 10:39:00
at 10:40:00
etc

How to do this? This is my current code:

let startTime = new Date(Math.ceil(new Date().getTime() / 60000) * 60000);
let source = Rx.Observable.timer(startTime, 60000).timeInterval().pluck('interval');


  this.Subscription = source
    .subscribe(data => { //code });

Answer 1

You could set a time out based on the amount of time till the next minute.

 var ONE_MINUTE_IN_MILLIS = 60000; var runMe = function() { var now = new Date().getTime(); console.log(new Date()); setTimeout(runMe, getNextMinute(now)); } var getNextMinute = function(now) { var timePassed = now % ONE_MINUTE_IN_MILLIS; return ONE_MINUTE_IN_MILLIS - timePassed; } runMe() 

Answer 2

You can start from something like that...

Rx
  .Observable
  .create((observer) => {
    const oneMin = 60000;
    let index = 0;

    const iterate = () => window.setTimeout(iteration, (
      oneMin - (Date.now() % oneMin)
    ));

    function iteration() {
      observer.next(index++);

      return iterate();
    }

    iteration();
  })
;

Answer 3

Set the subscription interval to 1000 and check when seconds change to 0. Here is a simple solution to do exactly what you want with minimum changes in your original code:

let startTime = new Date(Math.ceil(new Date().getTime() / 60000) * 60000);
let source = Observable.timer(startTime, 1000);
this.Subscription = source.subscribe(
    ticks => {
        if((ticks % 60) === 0) {
            console.log('Current Seconds is 0'); 
            // Perform your action here.
        }
    }
);

---

Here is a working plunk: DEMO

Answer 4

I have changed Faisal's solution and now it works ok, also it starts instantly and there is no problem with accumulating offset:

  let startTime = new Date();
  this.Source = Rx.Observable.timer(startTime, 1000).timeInterval().pluck('interval');

  this.Subscription = this.Source
    .subscribe(data => {
      if (Math.floor(this.LastPing.getTime() / 60000) * 60000 != Math.floor(new Date().getTime() / 60000) * 60000) {
        this.LastPing = new Date();
        //rest of the code        
      }
    });

Answer 5

Try something like this, though, as @Hitmands stated, you'll never get full precision :

 let date = new Date(), remainingSeconds = 60 - date.getSeconds(); function myFunc () { console.log(new Date()); } myFunc(); setTimeout(() => { myFunc(); setInterval(myFunc, 60000); }, remainingSeconds * 1000);