Cooldown

This rule allows you to enforce minimum rest periods between different types of work. It works by defining what triggers a cooldown (starts) and what should be avoided during that cooldown period (ends). This is useful for ensuring employees have adequate rest between demanding shifts, preventing burnout, and complying with labor regulations.

Rule schema

object

Used to define required or desired rest between working shifts.

Show properties

string

required

Unique identifier for the rule.

array of string

Labels for the rule. Labels can be used to group rules together. For example, if multiple rules are related to the same shift type, they can all be labeled with the same label.

required

The importance of the rule. The higher the importance, the more it will be taking the rule into account. Under strict importance, the rule may never be violated.

object

Filters to determine the scope of the rule. Used to decide which employees and which work the rule should be applied to.

Show filters – properties

object

Filters entities by id and label.

Show employees – properties

array of string

Entity ids to match.

array of string

Entity labels to match.

object

Show matchTypes – properties

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the id filters. For example, if set to NONE, entities with the specified ids will be excluded. Default: “ANY”.

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the label filters. For example, if set to ANY, entities that have any of the specified labels will be included. Default: “ANY”.

object

Defines filtering for specific work that the rule should be applied to. For example, it can be used to apply the rule only to work carried out in specific roles.

Show work – properties

object

Used to apply the rule only to work carried out in specific roles.

Show roles – properties

array of string

List of relevant role ids.

object

Used to apply the rule only to work carried out with specific workload categories.

Show workloads – properties

array of string

If specified, the shift must have at least one of the workload categories specified in this list.

object

required

Defines the desired minimum duration of the cooldown. Can be defined in either hours or days.

Show targets – properties

number

Minimum number of hours that the cooldown should last.

integer

Minimum number of days that the cooldown should last.

object

List of periods in the schedule. Periods can be defined explicitly or through a recurrent definition (for example, to generate weeks).

Show periods – properties

object

List of days in the schedule. Each day will become one period. By default, each period will last the entire day. If a startTime and/or endTime are specified, these will apply to each period.

Show days – properties

array of date (date)

List of dates in the schedule. Only allowed in CALENDAR payloads.

array of dayIndex

List of day indices in the schedule. Only allowed in RECURRING payloads.

array of dayOfWeek

List of days of the week. Will apply to all days in the schedule that match any of the specified weekdays.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

array of object

List of custom period definitions. Each custom period definition defines one period in the schedule.

Show customDefinitions – item structure

object

Describes one day in the schedule.

Show startDay – properties

string (date)

Date specified in ISO8601 format (YYYY-MM-DD). Only available in CALENDAR schedules.

integer

Day index relative to the horizon start day (starts at 0). Only available in RECURRING schedules.

object

Describes one day in the schedule.

Show endDay – properties

string (date)

Date specified in ISO8601 format (YYYY-MM-DD). Only available in CALENDAR schedules.

integer

Day index relative to the horizon start day (starts at 0). Only available in RECURRING schedules.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

boolean

If true, the startTime and endTime will be applied to each individual day in the period. If false, the startTime will apply to the first day and the endTime will apply to the last day. Default: false.

object

A recurrent definition to easily create a set of similar periods.

Show recurrentDefinition – properties

integer

required

The number of days in each period.

integer

The number of days between the start of each period. If not specified, this defaults to the value of daysPerPeriod, creating non-overlapping consecutive periods. Setting daysBetweenStarts to 1 will create a sliding window of periods.

object

Describes one day in the schedule.

Show startDay – properties

string (date)

Date specified in ISO8601 format (YYYY-MM-DD). Only available in CALENDAR schedules.

integer

Day index relative to the horizon start day (starts at 0). Only available in RECURRING schedules.

object

Describes one day in the schedule.

Show endDay – properties

string (date)

Date specified in ISO8601 format (YYYY-MM-DD). Only available in CALENDAR schedules.

integer

Day index relative to the horizon start day (starts at 0). Only available in RECURRING schedules.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

boolean

array of string

Provide labels to re-use periods that were defined in the configuration.

object

Defines the types of work that will trigger a cooldown. Currently, only filters on shifts are supported as starts.

Show starts – properties

object

Filters entities by id and label.

Show shifts – properties

array of string

Entity ids to match.

array of string

Entity labels to match.

object

Show matchTypes – properties

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the id filters. For example, if set to NONE, entities with the specified ids will be excluded. Default: “ANY”.

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the label filters. For example, if set to ANY, entities that have any of the specified labels will be included. Default: “ANY”.

object

Defines the types of work that should be avoided during a cooldown. Currently, only filters on shifts are supported as ends.

Show ends – properties

object

Filters entities by id and label.

Show shifts – properties

array of string

Entity ids to match.

array of string

Entity labels to match.

object

Show matchTypes – properties

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the id filters. For example, if set to NONE, entities with the specified ids will be excluded. Default: “ANY”.

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the label filters. For example, if set to ANY, entities that have any of the specified labels will be included. Default: “ANY”.

Basic cooldown between shifts

The simplest use case is to require a minimum rest period between any two shifts. This ensures employees have adequate time to recover between work periods. When you omit the starts and ends sections, the rule applies to all shifts.

The rule below requires a minimum of 12 hours of rest between any two shifts. After an employee finishes any shift, they cannot start another shift until at least 12 hours have passed.

{
  "id": "cd-min-12h-rest",
  "importance": "STRICT",
  "targets": {
    "minHours": 12
  }
}

Cooldown between specific shift types

You can define cooldowns that only apply between specific types of shifts. For example, you might want a longer cooldown after night shifts before morning shifts.

The rule below requires at least 16 hours of rest after a night shift before an employee can work a morning shift. This helps ensure employees have adequate time to adjust their sleep schedule.

{
  "id": "cd-night-to-morning",
  "importance": "STRICT",
  "targets": {
    "minHours": 16
  },
  "starts": {
    "shifts": {
      "labels": ["night"]
    }
  },
  "ends": {
    "shifts": {
      "labels": ["morning"]
    }
  }
}

Cooldown measured in days

Instead of specifying the cooldown in hours, you can specify it in days. This is useful for ensuring employees have full days off between certain types of work.

The rule below requires at least 2 days without a shift after working a weekend shift before an employee can work another weekend shift. This helps distribute weekend work more evenly among employees.

{
  "id": "cd-weekend-2-days",
  "importance": "STRICT",
  "targets": {
    "minDays": 2
  },
  "starts": {
    "shifts": {
      "labels": ["weekend"]
    }
  },
  "ends": {
    "shifts": {
      "labels": ["weekend"]
    }
  }
}

Complex cooldown scenarios

You can create more complex cooldown rules by combining different shift types in the starts and ends sections. This allows you to model sophisticated rest requirements.

The rule below requires at least 48 hours of rest after working any intensive shift (like emergency shifts or long shifts) before an employee can work another intensive shift. This helps prevent employee burnout from demanding work.

{
  "id": "cd-intensive-48h",
  "importance": "STRICT",
  "targets": {
    "minHours": 48
  },
  "starts": {
    "shifts": {
      "labels": ["intensive"]
    }
  },
  "ends": {
    "shifts": {
      "labels": ["intensive"]
    }
  }
}

Soft cooldown rules

While cooldown rules are often used with STRICT importance to enforce mandatory rest periods, you can also use them with other importance levels to encourage, but not strictly require, rest periods.

The rule below encourages, but doesn’t strictly require, at least 10 hours of rest after a night shift before an employee can work a morning shift. The solver will try to achieve this, but may violate it if necessary to satisfy other rules.

{
  "id": "cd-soft-night-to-morning",
  "importance": "MEDIUM",
  "targets": {
    "minHours": 10
  },
  "starts": {
    "shifts": {
      "labels": ["night"]
    }
  },
  "ends": {
    "shifts": {
      "labels": ["morning"]
    }
  }
}

Cooldown with specific shift IDs

You can also target specific shifts by their IDs, giving you fine-grained control over which shifts trigger cooldowns and which shifts are restricted during cooldown periods.

The rule below requires at least 8 hours of rest after a specific early morning shift (shift-1) before an employee can work a specific evening shift (shift-2). This is useful when you have specific shift pairs that should not be scheduled too close together.

{
  "id": "cd-specific-shifts",
  "importance": "STRICT",
  "targets": {
    "minHours": 8
  },
  "starts": {
    "shifts": {
      "ids": ["shift-1"]
    }
  },
  "ends": {
    "shifts": {
      "ids": ["shift-2"]
    }
  }
}

Cooldown with filters

You can also limit a cooldown rule to apply only to work carried out in specific roles.

The rule below requires a minimum of 16 hours of rest between any two shifts worked in role role-1. Shifts worked in other roles are not considered by this rule.

{
  "id": "cd-min-16h-rest-role-1",
  "importance": "STRICT",
  "filters": {
    "work": {
      "roles": {
        "ids": ["role-1"]
      }
    }
  },
  "targets": {
    "minHours": 16
  }
}

Metrics

The following status metrics are available for tracking on Cooldown rules:

Metric key	Description
`COOLDOWN.MISSING_DAYS`	Total number of required cooldown days that are missing.
`COOLDOWN.MISSING_MINUTES`	Total number of required cooldown minutes that are missing.
`COOLDOWN.VIOLATIONS`	Number of cooldowns that are shorter than required.

Getting started

Entities

Concepts

Reasoning

Status updates

Rule schema

Basic cooldown between shifts

Cooldown between specific shift types

Cooldown measured in days

Complex cooldown scenarios

Soft cooldown rules

Cooldown with specific shift IDs

Cooldown with filters

Metrics