[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) › fixed

```ts
function fixed(interval: Duration): Schedule<number>;
```

Defined in: [packages/common/src/Schedule.ts:345](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Schedule.ts#L345)

Fixed interval schedule aligned to time windows.

Recurs on a fixed interval, outputting the repetition count (0, 1, 2, ...).
Unlike [spaced](https://evolu.dev/docs/api-reference/common/Schedule/functions/spaced), which waits a duration _after_ each execution, `fixed`
maintains a consistent cadence from when the schedule started.

If execution takes longer than the interval, the next execution happens
immediately but subsequent runs still align to the original window
boundaries. This prevents "pile-up" while maintaining predictable timing.

### Example

```ts
// Health check every 5 seconds, aligned to windows
const healthCheck = take(10)(fixed("5s"));

// Cron-like behavior: run at consistent intervals
const cronLike = fixed("1m");
```