{
  "$comment": "Machine-readable companion to https://valem.run/calculators/belgium/holiday-entitlement. Formula, inputs, outputs, engine-verified test vectors, cited sources and the re-runnable Valem ModelSpec behind the page.",
  "url": "https://valem.run/calculators/belgium/holiday-entitlement",
  "dataUrl": "https://valem.run/calculators/belgium/holiday-entitlement.json",
  "license": {
    "name": "CC BY 4.0",
    "url": "https://creativecommons.org/licenses/by/4.0/",
    "attribution": "Belgium vacances annuelles model by Valem (https://valem.run/calculators/belgium/holiday-entitlement), CC BY 4.0.",
    "note": "Covers the model — the expression of each rule and the arrangement of the catalog. The rates and thresholds themselves are law and are not licensed by anyone; the cited sources are where they come from."
  },
  "verificationUrl": "https://valem.run/calculators/belgium/holiday-entitlement/verify",
  "country": "belgium",
  "countryName": "Belgium",
  "formula": "holiday-entitlement",
  "formulaName": "Vacances annuelles",
  "title": "Calcul jours de vacances 2026 — Belgium annual leave (20 days)",
  "answer": "In Belgium this year’s statutory leave depends on last year’s work: days worked or assimilated in the previous calendar year convert through the ONVA table to at most 20 days on a full-time five-day week (231 days or more gives the full 20). The maximum is four weeks in any working regime.",
  "lang": "en",
  "currency": "EUR",
  "taxYear": "2026",
  "verification": {
    "claim": "internal-consistency",
    "statement": "The Valem engine reproduces this model's stated formula through 8 self-test cases (below, and re-runnable against the spec). That asserts internal consistency, NOT that the formula matches current law — the cited sources are the evidence for that, and carry the date each was last checked.",
    "selfTestCases": 8,
    "ratesAreIllustrative": false,
    "sourcesCheckedOn": "2026-10-12"
  },
  "sources": [
    {
      "label": "ONVA / RJV — Calcul des jours de vacances: table of days worked to leave days, and the 4-week maximum by working regime",
      "url": "https://www.onva.fgov.be/fr/ouvriers/duree-de-vacances/calcul-des-jours-de-vacances",
      "checked": "2026-10-12"
    }
  ],
  "terminalOutput": "daysRemaining",
  "headlineOutput": "daysEntitled",
  "inputs": [
    {
      "name": "workDaysReferenceYear",
      "type": "number",
      "label": "Days worked or assimilated LAST year (full-time five-day equivalent)",
      "minimum": 0,
      "maximum": 366
    },
    {
      "name": "daysPerWeek",
      "type": "number",
      "label": "Working days in your week this year",
      "minimum": 1,
      "maximum": 6
    },
    {
      "name": "daysTaken",
      "type": "number",
      "label": "Days already taken",
      "minimum": 0
    }
  ],
  "outputs": [
    {
      "name": "fiveDayEquivalentDays",
      "type": "number",
      "formula": "($d := $n(workDaysReferenceYear); $count([$const.bandFloor1, $const.bandFloor2, $const.bandFloor3, $const.bandFloor4, $const.bandFloor5, $const.bandFloor6, $const.bandFloor7, $const.bandFloor8, $const.bandFloor9, $const.bandFloor10, $const.bandFloor11, $const.bandFloor12, $const.bandFloor13, $const.bandFloor14, $const.bandFloor15, $const.bandFloor16, $const.bandFloor17, $const.bandFloor18, $const.bandFloor19, $const.bandFloor20][$ <= $d]))"
    },
    {
      "name": "daysEntitled",
      "type": "number",
      "formula": "$round(fiveDayEquivalentDays * $n(daysPerWeek) / $const.fullTimeDaysPerWeek, 1)"
    },
    {
      "name": "daysRemaining",
      "type": "number",
      "formula": "($r := daysEntitled - $n(daysTaken); $r < 0 ? 0 : $round($r, 1))"
    }
  ],
  "testCases": [
    {
      "description": "BE1 a full year (260 days): 20 days of leave",
      "given": {
        "workDaysReferenceYear": 260,
        "daysPerWeek": 5,
        "daysTaken": 0
      },
      "expect": {
        "fiveDayEquivalentDays": 20,
        "daysEntitled": 20
      }
    },
    {
      "description": "BE2 231 days is still the full 20",
      "given": {
        "workDaysReferenceYear": 231,
        "daysPerWeek": 5,
        "daysTaken": 0
      },
      "expect": {
        "daysEntitled": 20
      }
    },
    {
      "description": "BE3 230 days drops to 19",
      "given": {
        "workDaysReferenceYear": 230,
        "daysPerWeek": 5,
        "daysTaken": 0
      },
      "expect": {
        "daysEntitled": 19
      }
    },
    {
      "description": "BE4 half a year (130 days): 10",
      "given": {
        "workDaysReferenceYear": 130,
        "daysPerWeek": 5,
        "daysTaken": 0
      },
      "expect": {
        "daysEntitled": 10
      }
    },
    {
      "description": "BE5 nine days earns nothing",
      "given": {
        "workDaysReferenceYear": 9,
        "daysPerWeek": 5,
        "daysTaken": 0
      },
      "expect": {
        "daysEntitled": 0
      }
    },
    {
      "description": "BE6 a six-day week: 24 days",
      "given": {
        "workDaysReferenceYear": 260,
        "daysPerWeek": 6,
        "daysTaken": 0
      },
      "expect": {
        "daysEntitled": 24
      }
    },
    {
      "description": "BE7 a four-day week: 16",
      "given": {
        "workDaysReferenceYear": 260,
        "daysPerWeek": 4,
        "daysTaken": 0
      },
      "expect": {
        "daysEntitled": 16
      }
    },
    {
      "description": "BE8 never negative",
      "given": {
        "workDaysReferenceYear": 260,
        "daysPerWeek": 5,
        "daysTaken": 40
      },
      "expect": {
        "daysRemaining": 0
      }
    }
  ],
  "spec": {
    "id": "holiday-entitlement-belgium",
    "version": "1.0.0",
    "schema": {
      "type": "object",
      "properties": {
        "workDaysReferenceYear": {
          "type": "number",
          "minimum": 0,
          "maximum": 366
        },
        "daysPerWeek": {
          "type": "number",
          "minimum": 1,
          "maximum": 6
        },
        "daysTaken": {
          "type": "number",
          "minimum": 0
        },
        "fiveDayEquivalentDays": {
          "type": "number",
          "readOnly": true
        },
        "daysEntitled": {
          "type": "number",
          "readOnly": true
        },
        "daysRemaining": {
          "type": "number",
          "readOnly": true
        }
      }
    },
    "constants": {
      "bandFloor1": 10,
      "bandFloor2": 20,
      "bandFloor3": 39,
      "bandFloor4": 48,
      "bandFloor5": 64,
      "bandFloor6": 77,
      "bandFloor7": 87,
      "bandFloor8": 97,
      "bandFloor9": 106,
      "bandFloor10": 125,
      "bandFloor11": 135,
      "bandFloor12": 144,
      "bandFloor13": 154,
      "bandFloor14": 163,
      "bandFloor15": 182,
      "bandFloor16": 192,
      "bandFloor17": 202,
      "bandFloor18": 212,
      "bandFloor19": 221,
      "bandFloor20": 231,
      "fullTimeDaysPerWeek": 5
    },
    "library": {
      "layers": [
        {
          "id": "statutory",
          "define": "(\n  /* Shared statutory helpers — the canonical copy (docs/sandbox/d8-statutory-families.md §5.4).\n     DO NOT EDIT A SPEC'S INLINED COPY. Edit this file and run `npm run sync:helpers`; a vitest\n     assertion and a Java assertion both require every inlined copy to be byte-identical to this one.\n\n     Why inlined rather than referenced: the `library` section's `ref` form — a library shared\n     between models — is still proposed, gated on the model-references design (see\n     ../../../../docs/design/library/jsonata-library.md). Inlining keeps each spec self-contained,\n     which is what lets `#e=` embedding, `#share=` import and MCP forking work with no resolver.\n\n     TWO TRAPS, both of which fail SILENTLY and both of which bit during the debt-payoff build:\n\n       1. A library function sees ONLY its arguments. It cannot read the consuming document — not\n          through a bare field name, not through `$`, not through `$$`. Everything these helpers\n          need is passed in. (`$const` is late-bound and so would resolve, but relying on it would\n          couple a shared helper to one spec's constant names.)\n       2. ONE null member wrecks a whole aggregate, and the two engines disagree about how. The JS\n          reference implementation THROWS (\"Argument 1 of function sum must be an array of\n          numbers\"); the Java port can instead yield null for the entire aggregate. Neither gives a\n          partial total, and the null-yielding form is the dangerous one because it is silent. So\n          callers coerce with `$n()` below before aggregating, which makes the behaviour identical\n          in both engines — measured, not assumed: see helpers.test.ts.\n\n       3. A PATH STEP DIRECTLY ON A CALL RESULT RETURNS NOTHING in the Java engine. This matters for\n          every caller of $amortize, which is the one helper here returning an object:\n\n              $amortize(p, r, n, 0).months            -> empty in Java, 360 in JS.  WRONG\n              ($a := $amortize(p, r, n, 0); $a.months) -> 360 in both.               RIGHT\n\n          Bind the result to a variable, then step into it. The JS reference accepts both forms, so\n          this is invisible until the page is served by the real engine, and it fails as a blank\n          field rather than an error. Measured with a probe, not inferred — the field simply does\n          not appear. */\n\n  /* Number coercion with an explicit zero default. The guard against trap 2. */\n  $n := function($v) { $v = null or $not($exists($v)) ? 0 : $number($v) };\n\n  /* ISO date -> its year / month / day parts. String slicing rather than $fromMillis formatting:\n     these are statutory dates (\"2026-04-06\"), and a timezone-sensitive round-trip through millis\n     can shift the day, which silently moves a service anniversary across a band boundary. */\n  $isoY := function($d) { $number($substring($d, 0, 4)) };\n  $isoM := function($d) { $number($substring($d, 5, 2)) };\n  $isoD := function($d) { $number($substring($d, 8, 2)) };\n\n  /* Whole years of completed service between two ISO dates. Counts an anniversary as reached only\n     when the month-and-day has arrived, which is what \"completed years of service\" means in every\n     severance statute — not a 365.25-day division, whose drift crosses a 5-year band boundary in\n     the wrong direction roughly one year in four. */\n  $yearsBetween := function($from, $to) { (\n    $y := $isoY($to) - $isoY($from);\n    $beforeAnniversary := $isoM($to) < $isoM($from)\n      or ($isoM($to) = $isoM($from) and $isoD($to) < $isoD($from));\n    $beforeAnniversary ? $y - 1 : $y\n  ) };\n\n  /* Whole completed months between two ISO dates, same convention. */\n  $monthsBetween := function($from, $to) { (\n    $m := ($isoY($to) - $isoY($from)) * 12 + ($isoM($to) - $isoM($from));\n    $isoD($to) < $isoD($from) ? $m - 1 : $m\n  ) };\n\n  /* Inclusive count of days between two ISO dates — both endpoints counted, because a leave year\n     runs from its first day to its last and an employee present on both is present for both.\n     Pro-rata accrual is then $proRataDays(a, b) / $proRataDays(yearStart, yearEnd). */\n  $proRataDays := function($from, $to) {\n    ($toMillis($to) - $toMillis($from)) / 86400000 + 1\n  };\n\n  /* Progressive charge across bands. `$bands` is ordered lowest-first, each {\"upTo\": n, \"rate\": r};\n     the final band's `upTo` is omitted or null to mean \"no ceiling\". Each band's rate applies ONLY\n     to the slice of the amount inside it — the single most common error in a hand-written bracket\n     walk is applying the top rate to the whole amount. Returns 0 for a non-positive amount. */\n  $bandedCharge := function($amount, $bands) { (\n    $a := $n($amount);\n    $a <= 0 ? 0 : $reduce($bands, function($acc, $band) { (\n      $ceiling := $exists($band.upTo) and $band.upTo != null ? $band.upTo : $a;\n      $top := $ceiling < $a ? $ceiling : $a;\n      $slice := $top - $acc.floor;\n      {\n        \"floor\": $top > $acc.floor ? $top : $acc.floor,\n        \"charge\": $acc.charge + ($slice > 0 ? $slice * $n($band.rate) : 0)\n      }\n    ) }, {\"floor\": 0, \"charge\": 0}).charge\n  ) };\n\n  /* Clamp into [floor, cap]. Either bound may be omitted (null) to leave that side open — a benefit\n     with a cap and no floor is as common as one with both. */\n  $clampFloorCap := function($value, $floor, $cap) { (\n    $v := $n($value);\n    $withFloor := $exists($floor) and $floor != null and $v < $floor ? $floor : $v;\n    $exists($cap) and $cap != null and $withFloor > $cap ? $cap : $withFloor\n  ) };\n\n  /* Level annuity payment for a principal over `$months` at `$annualRatePct` nominal, compounded\n     monthly. Falls back to straight-line division at a zero rate, where the standard formula\n     divides by zero. */\n  $annuityPayment := function($principal, $annualRatePct, $months) { (\n    $p := $n($principal);\n    $m := $n($months);\n    $i := $n($annualRatePct) / 1200;\n    $m <= 0 ? 0 : ($i = 0 ? $p / $m : $p * $i * $power(1 + $i, $m) / ($power(1 + $i, $m) - 1))\n  ) };\n\n  /* Amortisation schedule: one row per month until the balance clears or `$months` is reached.\n     Returns {\"payment\", \"months\", \"totalInterest\", \"schedule\": [{month, interest, principal,\n     balance}]}. `$extra` is an optional monthly overpayment.\n\n     A real month-by-month fold rather than a closed form, because an overpayment changes every\n     later row — the same reason debt-payoff simulates. Bounded by `$months`, so it always\n     terminates. */\n  $amortize := function($principal, $annualRatePct, $months, $extra) { (\n    $i := $n($annualRatePct) / 1200;\n    $pay := $annuityPayment($principal, $annualRatePct, $months) + $n($extra);\n    $r := $reduce([1..$n($months)], function($acc, $month) {\n      $acc.balance <= 0 ? $acc : (\n        /* The running balance is kept UNROUNDED and only the emitted row is rounded. Rounding the\n           balance each month instead accumulates drift: at 200,000 over 360 months it left 2.83\n           still owing in the final row, which would break the \"final balance is zero\" invariant\n           (§7.3) and look to a reader like the schedule does not pay the loan off. Lenders compute\n           on the exact balance and adjust the last payment, which is what this does. */\n        $interest := $acc.balance * $i;\n        $due := $acc.balance + $interest < $pay ? $acc.balance + $interest : $pay;\n        $principalPart := $due - $interest;\n        $balance := $acc.balance - $principalPart;\n        {\n          \"balance\": $balance,\n          \"totalInterest\": $acc.totalInterest + $interest,\n          \"schedule\": $append($acc.schedule, [{\n            \"month\": $month,\n            \"interest\": $round($interest, 2),\n            \"principal\": $round($principalPart, 2),\n            \"balance\": $round($balance, 2)\n          }])\n        }\n      )\n    }, {\"balance\": $n($principal), \"totalInterest\": 0, \"schedule\": []});\n    {\n      \"payment\": $round($pay, 2),\n      \"months\": $count($r.schedule),\n      \"totalInterest\": $round($r.totalInterest, 2),\n      \"schedule\": [$r.schedule]\n    }\n  ) };\n\n  [\"n\", \"isoY\", \"isoM\", \"isoD\", \"yearsBetween\", \"monthsBetween\", \"proRataDays\",\n   \"bandedCharge\", \"clampFloorCap\", \"annuityPayment\", \"amortize\"]\n)\n"
        }
      ]
    },
    "defaultValues": [
      {
        "path": "$",
        "expr": "{ 'workDaysReferenceYear': 260, 'daysPerWeek': 5, 'daysTaken': 0 }"
      }
    ],
    "derivations": [
      {
        "path": "$.fiveDayEquivalentDays",
        "expr": "($d := $n(workDaysReferenceYear); $count([$const.bandFloor1, $const.bandFloor2, $const.bandFloor3, $const.bandFloor4, $const.bandFloor5, $const.bandFloor6, $const.bandFloor7, $const.bandFloor8, $const.bandFloor9, $const.bandFloor10, $const.bandFloor11, $const.bandFloor12, $const.bandFloor13, $const.bandFloor14, $const.bandFloor15, $const.bandFloor16, $const.bandFloor17, $const.bandFloor18, $const.bandFloor19, $const.bandFloor20][$ <= $d]))"
      },
      {
        "path": "$.daysEntitled",
        "expr": "$round(fiveDayEquivalentDays * $n(daysPerWeek) / $const.fullTimeDaysPerWeek, 1)"
      },
      {
        "path": "$.daysRemaining",
        "expr": "($r := daysEntitled - $n(daysTaken); $r < 0 ? 0 : $round($r, 1))"
      }
    ],
    "constraints": [],
    "viewDefinition": {
      "renderer": "builtin",
      "defaultView": "main",
      "views": [
        {
          "id": "main",
          "label": "Vacances annuelles",
          "layout": "vertical",
          "components": [
            {
              "id": "note",
              "type": "staticText",
              "text": "ONVA: «Le nombre de jours de vacances (durée de vacances) est déterminé en fonction des prestations de l’exercice de vacances» — the YEAR BEFORE. Days worked, plus assimilated days such as sick leave and the previous year’s holidays, are counted as a full-time five-day equivalent and converted by table: 231 days or more give the full 20; 221–230 give 19; and so on down to 0 for fewer than 10. The maximum is 4 weeks a year in any regime — 24 days on a six-day week, 16 on four, 12 on three."
            },
            {
              "id": "inputs",
              "type": "fieldSet",
              "label": "Your details",
              "components": [
                {
                  "id": "workDays",
                  "type": "numericField",
                  "label": "Days worked or assimilated LAST year (full-time five-day equivalent)",
                  "bind": "$.workDaysReferenceYear",
                  "helperText": "A full year of five-day work is about 260; anything from 231 up gives the maximum."
                },
                {
                  "id": "days",
                  "type": "numericField",
                  "label": "Working days in your week this year",
                  "bind": "$.daysPerWeek"
                },
                {
                  "id": "daysTaken",
                  "type": "numericField",
                  "label": "Days already taken",
                  "bind": "$.daysTaken"
                }
              ]
            },
            {
              "id": "sep",
              "type": "separatorLine"
            },
            {
              "id": "entitledTile",
              "type": "statTile",
              "label": "Days of leave this year",
              "value": "$.daysEntitled"
            },
            {
              "id": "remainingTile",
              "type": "statTile",
              "label": "Days remaining",
              "value": "$.daysRemaining"
            },
            {
              "id": "breakdown",
              "type": "keyValueList",
              "label": "How that is worked out",
              "items": [
                {
                  "label": "Leave days in five-day terms (from the table)",
                  "value": "$.fiveDayEquivalentDays"
                }
              ]
            },
            {
              "id": "assumptions",
              "type": "staticText",
              "text": "The table is ONVA’s, for blue-collar workers (ouvriers), whose holiday pay it administers; white-collar employees reach the same 20 days for a full year by a months-based count paid through their employer. A first job or a return to work in the year can open “European” or supplementary holidays, which are not modelled. Leave must be taken in the calendar year. Holiday pay (pécule de vacances) is not computed here."
            },
            {
              "id": "sources",
              "type": "sourceList",
              "label": "Sources",
              "layers": 1,
              "exempt": [
                "fullTimeDaysPerWeek"
              ],
              "items": [
                {
                  "label": "ONVA / RJV — Calcul des jours de vacances: table of days worked to leave days, and the 4-week maximum by working regime",
                  "url": "https://www.onva.fgov.be/fr/ouvriers/duree-de-vacances/calcul-des-jours-de-vacances",
                  "date": "2026-10-12",
                  "covers": [
                    "bandFloor1",
                    "bandFloor2",
                    "bandFloor3",
                    "bandFloor4",
                    "bandFloor5",
                    "bandFloor6",
                    "bandFloor7",
                    "bandFloor8",
                    "bandFloor9",
                    "bandFloor10",
                    "bandFloor11",
                    "bandFloor12",
                    "bandFloor13",
                    "bandFloor14",
                    "bandFloor15",
                    "bandFloor16",
                    "bandFloor17",
                    "bandFloor18",
                    "bandFloor19",
                    "bandFloor20"
                  ]
                }
              ]
            }
          ]
        }
      ]
    },
    "tests": [
      {
        "description": "BE1 a full year (260 days): 20 days of leave",
        "given": {
          "$.workDaysReferenceYear": 260,
          "$.daysPerWeek": 5,
          "$.daysTaken": 0
        },
        "expect": {
          "$.fiveDayEquivalentDays": 20,
          "$.daysEntitled": 20
        }
      },
      {
        "description": "BE2 231 days is still the full 20",
        "given": {
          "$.workDaysReferenceYear": 231,
          "$.daysPerWeek": 5,
          "$.daysTaken": 0
        },
        "expect": {
          "$.daysEntitled": 20
        }
      },
      {
        "description": "BE3 230 days drops to 19",
        "given": {
          "$.workDaysReferenceYear": 230,
          "$.daysPerWeek": 5,
          "$.daysTaken": 0
        },
        "expect": {
          "$.daysEntitled": 19
        }
      },
      {
        "description": "BE4 half a year (130 days): 10",
        "given": {
          "$.workDaysReferenceYear": 130,
          "$.daysPerWeek": 5,
          "$.daysTaken": 0
        },
        "expect": {
          "$.daysEntitled": 10
        }
      },
      {
        "description": "BE5 nine days earns nothing",
        "given": {
          "$.workDaysReferenceYear": 9,
          "$.daysPerWeek": 5,
          "$.daysTaken": 0
        },
        "expect": {
          "$.daysEntitled": 0
        }
      },
      {
        "description": "BE6 a six-day week: 24 days",
        "given": {
          "$.workDaysReferenceYear": 260,
          "$.daysPerWeek": 6,
          "$.daysTaken": 0
        },
        "expect": {
          "$.daysEntitled": 24
        }
      },
      {
        "description": "BE7 a four-day week: 16",
        "given": {
          "$.workDaysReferenceYear": 260,
          "$.daysPerWeek": 4,
          "$.daysTaken": 0
        },
        "expect": {
          "$.daysEntitled": 16
        }
      },
      {
        "description": "BE8 never negative",
        "given": {
          "$.workDaysReferenceYear": 260,
          "$.daysPerWeek": 5,
          "$.daysTaken": 40
        },
        "expect": {
          "$.daysRemaining": 0
        }
      }
    ]
  }
}