[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › Schedule Composable scheduling strategies. ## Composition | Name | Description | | ------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------- | | [ScheduleStep](https://evolu.dev/docs/api-reference/common/Schedule/interfaces/ScheduleStep) | Base interface for schedule-based task helpers. | | [intersectSchedules](https://evolu.dev/docs/api-reference/common/Schedule/functions/intersectSchedules) | Combines two schedules with AND semantics. | | [sequenceSchedules](https://evolu.dev/docs/api-reference/common/Schedule/functions/sequenceSchedules) | Sequences schedules: runs each until it stops, then continues with the next. | | [unionSchedules](https://evolu.dev/docs/api-reference/common/Schedule/functions/unionSchedules) | Combines two schedules with OR semantics. | | [whenInput](https://evolu.dev/docs/api-reference/common/Schedule/functions/whenInput) | Selects between two schedules based on input. | ## Constructors | Name | Description | | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ | | [elapsed](https://evolu.dev/docs/api-reference/common/Schedule/variables/elapsed) | A schedule that outputs the total elapsed time since the schedule started. | | [forever](https://evolu.dev/docs/api-reference/common/Schedule/variables/forever) | A schedule that never stops and has no delay. | | [once](https://evolu.dev/docs/api-reference/common/Schedule/variables/once) | A schedule that runs exactly once with no delay. | | [always](https://evolu.dev/docs/api-reference/common/Schedule/functions/always) | A schedule that always outputs a constant value. | | [during](https://evolu.dev/docs/api-reference/common/Schedule/functions/during) | A schedule that runs for a specified duration then stops. | | [exponential](https://evolu.dev/docs/api-reference/common/Schedule/functions/exponential) | Exponential backoff schedule. | | [fibonacci](https://evolu.dev/docs/api-reference/common/Schedule/functions/fibonacci) | Fibonacci backoff schedule. | | [fixed](https://evolu.dev/docs/api-reference/common/Schedule/functions/fixed) | Fixed interval schedule aligned to time windows. | | [fromDelay](https://evolu.dev/docs/api-reference/common/Schedule/functions/fromDelay) | A schedule that runs once with a single delay. | | [fromDelays](https://evolu.dev/docs/api-reference/common/Schedule/functions/fromDelays) | A schedule that runs through a sequence of delays. | | [linear](https://evolu.dev/docs/api-reference/common/Schedule/functions/linear) | Linear backoff schedule. | | [passthrough](https://evolu.dev/docs/api-reference/common/Schedule/functions/passthrough) | Creates a schedule that outputs its input, or wraps an existing schedule to output input instead of the original output. | | [recurs](https://evolu.dev/docs/api-reference/common/Schedule/functions/recurs) | A schedule that recurs a fixed number of times. | | [spaced](https://evolu.dev/docs/api-reference/common/Schedule/functions/spaced) | Constant delay schedule. | | [unfoldSchedule](https://evolu.dev/docs/api-reference/common/Schedule/functions/unfoldSchedule) | Creates a schedule by unfolding a state. | | [windowed](https://evolu.dev/docs/api-reference/common/Schedule/functions/windowed) | Divides the timeline into fixed windows and sleeps until the next boundary. | ## Limiting | Function | Description | | -------------------------------------------------------------------------- | ---------------------------------------------------- | | [maxDelay](https://evolu.dev/docs/api-reference/common/Schedule/functions/maxDelay) | Caps the delay to a maximum value. | | [maxElapsed](https://evolu.dev/docs/api-reference/common/Schedule/functions/maxElapsed) | Limits schedule execution to a maximum elapsed time. | | [take](https://evolu.dev/docs/api-reference/common/Schedule/functions/take) | Limits a schedule to a maximum number of attempts. | ## Delay | Function | Description | | ---------------------------------------------------------------------------- | ---------------------------------------------------- | | [addDelay](https://evolu.dev/docs/api-reference/common/Schedule/functions/addDelay) | Adds a fixed delay to the schedule's existing delay. | | [compensate](https://evolu.dev/docs/api-reference/common/Schedule/functions/compensate) | Adjusts delay by subtracting execution time. | | [delayed](https://evolu.dev/docs/api-reference/common/Schedule/functions/delayed) | Adds an initial delay before the first attempt. | | [jitter](https://evolu.dev/docs/api-reference/common/Schedule/functions/jitter) | Adds randomized jitter to delays. | | [modifyDelay](https://evolu.dev/docs/api-reference/common/Schedule/functions/modifyDelay) | Transforms the delay of a schedule. | ## Filtering | Function | Description | | -------------------------------------------------------------------------------------------- | ------------------------------------------------- | | [untilScheduleInput](https://evolu.dev/docs/api-reference/common/Schedule/functions/untilScheduleInput) | Continues until the input satisfies a predicate. | | [untilScheduleOutput](https://evolu.dev/docs/api-reference/common/Schedule/functions/untilScheduleOutput) | Continues until the output satisfies a predicate. | | [whileScheduleInput](https://evolu.dev/docs/api-reference/common/Schedule/functions/whileScheduleInput) | Continues while the input satisfies a predicate. | | [whileScheduleOutput](https://evolu.dev/docs/api-reference/common/Schedule/functions/whileScheduleOutput) | Continues while the output satisfies a predicate. | ## State | Function | Description | | ------------------------------------------------------------------------------------------ | ------------------------------------------------- | | [resetScheduleAfter](https://evolu.dev/docs/api-reference/common/Schedule/functions/resetScheduleAfter) | Resets the schedule after a period of inactivity. | ## Transform | Function | Description | | ------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------ | | [delays](https://evolu.dev/docs/api-reference/common/Schedule/functions/delays) | Outputs the delay between recurrences. | | [foldSchedule](https://evolu.dev/docs/api-reference/common/Schedule/functions/foldSchedule) | Folds over the outputs of a schedule, accumulating state. | | [mapSchedule](https://evolu.dev/docs/api-reference/common/Schedule/functions/mapSchedule) | Transforms the output of a schedule. | | [passthrough](https://evolu.dev/docs/api-reference/common/Schedule/functions/passthrough) | Creates a schedule that outputs its input, or wraps an existing schedule to output input instead of the original output. | | [repetitions](https://evolu.dev/docs/api-reference/common/Schedule/functions/repetitions) | Wraps a schedule to output the number of repetitions instead of original output. | ## Collection | Function | Description | | ---------------------------------------------------------------------------------------------------------- | ------------------------------------------------ | | [collectAllScheduleOutputs](https://evolu.dev/docs/api-reference/common/Schedule/functions/collectAllScheduleOutputs) | Collects all outputs into an array. | | [collectScheduleInputs](https://evolu.dev/docs/api-reference/common/Schedule/functions/collectScheduleInputs) | Collects all inputs into an array. | | [collectUntilScheduleOutput](https://evolu.dev/docs/api-reference/common/Schedule/functions/collectUntilScheduleOutput) | Collects outputs until a predicate becomes true. | | [collectWhileScheduleOutput](https://evolu.dev/docs/api-reference/common/Schedule/functions/collectWhileScheduleOutput) | Collects outputs while a predicate is true. | ## Side effects | Function | Description | | ---------------------------------------------------------------------------------------- | ---------------------------------------------------------------------- | | [tapScheduleInput](https://evolu.dev/docs/api-reference/common/Schedule/functions/tapScheduleInput) | Executes a side effect for every input without altering the schedule. | | [tapScheduleOutput](https://evolu.dev/docs/api-reference/common/Schedule/functions/tapScheduleOutput) | Executes a side effect for every output without altering the schedule. | ## Retry Strategies | Variable | Description | | -------------------------------------------------------------------------------------- | ---------------------------- | | [retryStrategyAws](https://evolu.dev/docs/api-reference/common/Schedule/variables/retryStrategyAws) | AWS standard retry strategy. | ## Type Aliases | Type Alias | Description | | --------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [Schedule](https://evolu.dev/docs/api-reference/common/Schedule/type-aliases/Schedule) | Composable scheduling strategies for [retry](https://evolu.dev/docs/api-reference/common/Task/functions/retry), [repeat](https://evolu.dev/docs/api-reference/common/Task/functions/repeat), rate limiting, and more. | | [ScheduleDeps](https://evolu.dev/docs/api-reference/common/Schedule/type-aliases/ScheduleDeps) | Dependencies provided to a [Schedule](https://evolu.dev/docs/api-reference/common/Schedule/type-aliases/Schedule). |