Interval as a Svelte Store

Component.svelte

<script>
  import { createIntervalStore } from './interval.store.ts'

  // Create interval of 6 seconds
  const interval = createIntervalStore(6000);

  $: $interval, doSomething();
</script>

interval.store.ts

import { readable } from 'svelte/store';

export const createIntervalStore = (duration: number) =>
  readable(new Date(), (setTime) => {
    let interval = setInterval(() => setTime(new Date()), duration);

    return () => clearInterval(interval);
  });