> For the complete documentation index, see [llms.txt](https://soufatn.gitbook.io/rxjs-book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://soufatn.gitbook.io/rxjs-book/summary/observable/observable_instance_methods/delay.md).

# delay

Time shifts the observable sequence by dueTime. The relative time intervals between the values are preserved.

\--OR--

Time shifts the observable sequence based on a subscription delay and a delay selector function for each element.

## Arguments

For delays with an absolute or relative time: 1. `dueTime` *(Date | Number)*: Absolute (specified as a Date object) or relative time (specified as an integer denoting milliseconds) by which to shift the observable sequence. 2. `[scheduler]` *(`Scheduler`)*: Scheduler to run the delay timers on. If not specified, the default scheduler is used.

For delays with a delay selector function: 1. `[subscriptionDelay]` *(`Observable`)*: Sequence indicating the delay for the subscription to the source. 2. `delayDurationSelector` *(`Function`)*: Selector function to retrieve a sequence indicating the delay for each given element.

## Returns

*(`Observable`)*: Time-shifted sequence.

## Example

### Using an absolute time to delay by a second

### Using an relatove time to delay by a second

```javascript
/* With subscriptionDelay */
var source = Rx.Observable
  .range(0, 3)
  .delay(
    Rx.Observable.timer(300),
    function (x) { return Rx.Observable.timer(x * 400); }
  )
  .timeInterval()
  .map(function (x) { return x.value + ':' + x.interval; });

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
    console.log('Completed');
  });


// => Next: 0:300
// => Next: 1:400
// => Next: 2:400
// => Completed
```

```javascript
/* Without subscriptionDelay */
var source = Rx.Observable
  .range(0, 3)
  .delay(function (x) { return Rx.Observable.timer(x * 400); })
  .timeInterval()
  .map(function (x) { return x.value + ':' + x.interval; });

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
    console.log('Completed');
  });

// => Next: 0:0
// => Next: 1:400
// => Next: 2:400
// => Completed
```