[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Schedule](https://evolu.dev/docs/api-reference/common/Schedule) › spaced

```ts
function spaced(
  duration: Duration,
): Schedule<
  number &
    Brand<"NonNaN"> &
    Brand<"Finite"> &
    Brand<"Int"> &
    Brand<"NonNegative"> &
    Brand<"LessThan281474976710655"> &
    Brand<"Millis">
>;
```

Defined in: [packages/common/src/Schedule.ts:258](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/Schedule.ts#L258)

Constant delay schedule.

Always waits the same duration after each execution completes. Never stops —
combine with [take](https://evolu.dev/docs/api-reference/common/Schedule/functions/take) or [maxElapsed](https://evolu.dev/docs/api-reference/common/Schedule/functions/maxElapsed) to limit.

### Constant spacing

```ts

// Poll every second, retry three times, or run a long-lived heartbeat.
const poll = spaced("1s");
const retry = take(3)(spaced("500ms"));
const heartbeat = spaced("30s");
const deps = testCreateDeps();

assertOk(poll(deps)(undefined), [1000, 1000]);
assertOk(retry(deps)(undefined), [500, 500]);
assertOk(heartbeat(deps)(undefined), [30000, 30000]);
```