Consecutive weekends off per period

There are different techniques for managing employee’s time off.

This guide shows you how to include consecutive weekends off per period. Consecutive weekends off per period can be specified per month or for the entire schedule.

Prerequisites

Learn how to configure an API Key to run the examples in this guide:

  1. Log in to Timefold Platform: app.timefold.ai

  2. From the Dashboard, click your tenant, and from the drop-down menu select Tenant Settings, then choose API Keys.

  3. Create a new API key or use an existing one. Ensure the list of models for the API key contains the Employee Shift Scheduling model.

In the examples, replace <API_KEY> with the API Key you just copied.

1. Define consecutive weekends off per period

Period rules are configured in contracts:

{
  "periodRules": [
    {
      "id": "min3ConsecutiveWeekendsOff",
      "period": "SCHEDULE",
      "consecutiveWeekendsOffLimit":
        {
          "consecutiveWeekendsOffMin": 3
        },
      "satisfiability": "REQUIRED"
    }
  ]
}

periodRules must include an ID.

period sets the period the rule applies to, for instance, DAY, WEEK, MONTH, SCHEDULE.

Further information about period:

DAY spans a single day and occurs every day in the schedule.

WEEK spans 7 days and occurs every week (including partial weeks) in the schedule. The default start of the week is Monday, but this can be overridden to any day in the week:

{
  "scheduleParameterization": {
    "weekStart": "THURSDAY"
  }
}

MONTH spans the entire month. MONTH has a variable number of days depending on the days in the month and occurs every month (including partial months) in the schedule.

SCHEDULE spans the entire schedule.

You can define custom periods to apply to this rule in the following way: 
{
  "scheduleParameterization": {
    "periods": [
      {
        "id": "PAY_PERIOD",
        "dateSpans": [
          {
            "start": "2023-01-01",
            "end": "2023-01-15"
          }
        ]
      }
    ]
  }
}

The start and end dates are inclusive.

The consecutiveWeekendsOffLimit object must include consecutiveWeekendsOffMin with the minimum number of consecutive weekends off. consecutiveWeekendsOffMin should be at least 2.

periodRules can include or exclude shifts based on shift tags.

{
  "periodRules": [
    {
      "id": "min3ConsecutiveWeekendsOff",
      "period": "SCHEDULE",
      "consecutiveWeekendsOffLimit":
        {
          "consecutiveWeekendsOffMin": 3
        },
      "satisfiability": "REQUIRED",
      "includeShiftTags": ["Part-time"],
      "shiftTagMatches": "ALL"
    }
  ]
}
Further information about including or excluding shifts with shift tags:

Shifts with specific tags can be included or excluded by the rule. Tags are defined in shifts:

{
  "shifts": [
    {
      "id": "2027-02-01",
      "start": "2027-02-01T09:00:00Z",
      "end": "2027-02-01T17:00:00Z",
      "tags": ["Part-time"]
    }
  ]
}

Use includeShiftTags to include shifts with specific tags or excludeShiftTags to exclude shifts with specific tags.

shiftTagMatches can be set to ALL or ANY. The default behavior for shiftTagMatches is ALL, and if omitted, the default ALL will be used.

The rule can define either includeShiftTags or excludeShiftTags, but not both.

{
  "includeShiftTags": ["Part-time", "Weekend"],
  "shiftTagMatches": "ALL"
}

With shiftTagMatches set to ALL, all tags defined by the rule’s includeShiftTags attribute must be present in the shift. With shiftTagMatches set to ANY, at least one tag defined by the rule’s includeShiftTags attribute must be present in the shift.

{
  "excludeShiftTags": ["Part-time", "Weekend"],
  "shiftTagMatches": "ALL"
}

With shiftTagMatches set to ALL, all tags defined by the rule’s excludeShiftTags attribute cannot be present in the shift. This is useful when you want to exclude things in combination with each other. For instance, excluding the shift tags Part-time and Weekend with shiftTagMatches set to All, will exclude shifts that include the tags Part-time and Weekend from the rule. Shifts tagged only Part-time or only Weekend will not be excluded.

With shiftTagMatches set to ANY, any of the tags defined by the rule’s excludeShiftTags attribute cannot be present in the shift. This is useful when you need to exclude tags regardless of their relationship to other tags. For instance, excluding the shift tags Part-time and Weekend with shiftTagMatches set to ANY, will exclude any shift that includes the tags Part-time or Weekend, whether they occur together or not.

The satisfiability of the rule can be REQUIRED or PREFERRED. If omitted, REQUIRED is the default.

2. Required consecutive weekends off per period

When the satisfiability of the rule is REQUIRED, the Consecutive weekends off per period not in required range for employee hard constraint is invoked, which makes sure the number of consecutive weekends off in the period is not below the limit specified in consecutiveWeekendsOffMin.

Shifts will be left unassigned if assigning them would break the Consecutive weekends off per period not in required range for employee constraint.

3. Preferred consecutive weekends off per period

When the satisfiability of the rule is PREFERRED, the Consecutive weekends off per period not in preferred range for employee soft constraint is invoked.

Every soft constraint has a weight that can be configured to change the relative importance of the constraint compared to other constraints.

Learn about constraint weights.
This rule is more likely to be satisfied for employees with a higher employee priority.

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