{
  "$comment": "Machine-readable companion to https://valem.run/calculators/japan/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/japan/holiday-entitlement",
  "dataUrl": "https://valem.run/calculators/japan/holiday-entitlement.json",
  "license": {
    "name": "CC BY 4.0",
    "url": "https://creativecommons.org/licenses/by/4.0/",
    "attribution": "Japan 年次有給休暇 model by Valem (https://valem.run/calculators/japan/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/japan/holiday-entitlement/verify",
  "country": "japan",
  "countryName": "Japan",
  "formula": "holiday-entitlement",
  "formulaName": "年次有給休暇",
  "title": "有給休暇の日数計算 2026 — 労基法第39条の付与表",
  "answer": "Article 39 of the Labour Standards Act grants ten working days of paid leave after six months of continuous service, provided you attended at least 80% of all working days. It then adds 1, 2, 4, 6, 8 and 10 days at one through six years past the six-month mark, so twenty days is the statutory ceiling however long you stay.",
  "lang": "en",
  "currency": "JPY",
  "taxYear": "2026",
  "verification": {
    "claim": "internal-consistency",
    "statement": "The Valem engine reproduces this model's stated formula through 9 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": 9,
    "ratesAreIllustrative": false,
    "sourcesCheckedOn": "2026-10-11"
  },
  "sources": [
    {
      "label": "労働基準法 第三十九条 — e-Gov (Labour Standards Act art. 39: the ten days, the six-month and 80% conditions, and the service-year table)",
      "url": "https://laws.e-gov.go.jp/law/322AC0000000049",
      "checked": "2026-10-11"
    }
  ],
  "terminalOutput": "daysRemaining",
  "headlineOutput": "daysEntitled",
  "inputs": [
    {
      "name": "serviceMonths",
      "type": "number",
      "label": "Months of continuous service",
      "minimum": 0,
      "maximum": 600
    },
    {
      "name": "attendanceRate",
      "type": "number",
      "label": "Attendance as a % of all working days",
      "minimum": 0,
      "maximum": 100
    },
    {
      "name": "daysTaken",
      "type": "number",
      "label": "Days already taken",
      "minimum": 0
    }
  ],
  "outputs": [
    {
      "name": "qualifies",
      "type": "boolean",
      "formula": "($n(serviceMonths) >= $const.qualifyingMonths and $n(attendanceRate) >= $const.attendancePercent)"
    },
    {
      "name": "yearsAfterQualifying",
      "type": "number",
      "formula": "($y := $floor(($n(serviceMonths) - $const.qualifyingMonths) / 12); $y < 0 ? 0 : $y)"
    },
    {
      "name": "addedDays",
      "type": "number",
      "formula": "(yearsAfterQualifying >= $const.bandYear6 ? $const.addAfter6Years : (yearsAfterQualifying = $const.bandYear5 ? $const.addAfter5Years : (yearsAfterQualifying = $const.bandYear4 ? $const.addAfter4Years : (yearsAfterQualifying = $const.bandYear3 ? $const.addAfter3Years : (yearsAfterQualifying = $const.bandYear2 ? $const.addAfter2Years : (yearsAfterQualifying = $const.bandYear1 ? $const.addAfter1Year : 0))))))"
    },
    {
      "name": "daysEntitled",
      "type": "number",
      "formula": "(qualifies = true ? $const.baseDays + addedDays : 0)"
    },
    {
      "name": "daysRemaining",
      "type": "number",
      "formula": "($r := daysEntitled - $n(daysTaken); $r < 0 ? 0 : $round($r, 1))"
    }
  ],
  "testCases": [
    {
      "description": "K1 under six months there is no entitlement at all",
      "given": {
        "serviceMonths": 5,
        "attendanceRate": 100,
        "daysTaken": 0
      },
      "expect": {
        "qualifies": false,
        "daysEntitled": 0
      }
    },
    {
      "description": "K2 at six months exactly, art. 39(1)'s ten working days",
      "given": {
        "serviceMonths": 6,
        "attendanceRate": 100,
        "daysTaken": 0
      },
      "expect": {
        "qualifies": true,
        "yearsAfterQualifying": 0,
        "daysEntitled": 10
      }
    },
    {
      "description": "K3 one year past the six-month mark adds one day",
      "given": {
        "serviceMonths": 18,
        "attendanceRate": 100,
        "daysTaken": 0
      },
      "expect": {
        "yearsAfterQualifying": 1,
        "addedDays": 1,
        "daysEntitled": 11
      }
    },
    {
      "description": "K4 the table is not linear: three years past adds four days, not three",
      "given": {
        "serviceMonths": 42,
        "attendanceRate": 100,
        "daysTaken": 0
      },
      "expect": {
        "yearsAfterQualifying": 3,
        "addedDays": 4,
        "daysEntitled": 14
      }
    },
    {
      "description": "K5 six years past the mark is the statutory ceiling of twenty",
      "given": {
        "serviceMonths": 78,
        "attendanceRate": 100,
        "daysTaken": 0
      },
      "expect": {
        "yearsAfterQualifying": 6,
        "addedDays": 10,
        "daysEntitled": 20
      }
    },
    {
      "description": "K6 and it plateaus: thirty years' service is still twenty days",
      "given": {
        "serviceMonths": 360,
        "attendanceRate": 100,
        "daysTaken": 0
      },
      "expect": {
        "daysEntitled": 20
      }
    },
    {
      "description": "K7 the 80% attendance test is a gate, not a reduction: 79% is nothing",
      "given": {
        "serviceMonths": 78,
        "attendanceRate": 79,
        "daysTaken": 0
      },
      "expect": {
        "qualifies": false,
        "daysEntitled": 0
      }
    },
    {
      "description": "K8 and 80% exactly qualifies in full — the statute says 八割以上, eight tenths or more",
      "given": {
        "serviceMonths": 78,
        "attendanceRate": 80,
        "daysTaken": 0
      },
      "expect": {
        "qualifies": true,
        "daysEntitled": 20
      }
    },
    {
      "description": "K9 days already taken come off the remainder, and it never goes negative",
      "given": {
        "serviceMonths": 78,
        "attendanceRate": 100,
        "daysTaken": 25
      },
      "expect": {
        "daysRemaining": 0
      }
    }
  ],
  "spec": {
    "id": "holiday-entitlement-japan",
    "version": "1.0.0",
    "schema": {
      "type": "object",
      "properties": {
        "serviceMonths": {
          "type": "number",
          "maximum": 600,
          "minimum": 0
        },
        "attendanceRate": {
          "type": "number",
          "maximum": 100,
          "minimum": 0
        },
        "daysTaken": {
          "type": "number",
          "minimum": 0
        },
        "qualifies": {
          "type": "boolean",
          "readOnly": true
        },
        "yearsAfterQualifying": {
          "type": "number",
          "readOnly": true
        },
        "addedDays": {
          "type": "number",
          "readOnly": true
        },
        "daysEntitled": {
          "type": "number",
          "readOnly": true
        },
        "daysRemaining": {
          "type": "number",
          "readOnly": true
        }
      }
    },
    "constants": {
      "baseDays": 10,
      "qualifyingMonths": 6,
      "attendancePercent": 80,
      "bandYear1": 1,
      "addAfter1Year": 1,
      "bandYear2": 2,
      "addAfter2Years": 2,
      "bandYear3": 3,
      "addAfter3Years": 4,
      "bandYear4": 4,
      "addAfter4Years": 6,
      "bandYear5": 5,
      "addAfter5Years": 8,
      "bandYear6": 6,
      "addAfter6Years": 10
    },
    "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": "{ 'serviceMonths': 18, 'attendanceRate': 100, 'daysTaken': 0 }"
      }
    ],
    "derivations": [
      {
        "path": "$.qualifies",
        "expr": "($n(serviceMonths) >= $const.qualifyingMonths and $n(attendanceRate) >= $const.attendancePercent)"
      },
      {
        "path": "$.yearsAfterQualifying",
        "expr": "($y := $floor(($n(serviceMonths) - $const.qualifyingMonths) / 12); $y < 0 ? 0 : $y)"
      },
      {
        "path": "$.addedDays",
        "expr": "(yearsAfterQualifying >= $const.bandYear6 ? $const.addAfter6Years : (yearsAfterQualifying = $const.bandYear5 ? $const.addAfter5Years : (yearsAfterQualifying = $const.bandYear4 ? $const.addAfter4Years : (yearsAfterQualifying = $const.bandYear3 ? $const.addAfter3Years : (yearsAfterQualifying = $const.bandYear2 ? $const.addAfter2Years : (yearsAfterQualifying = $const.bandYear1 ? $const.addAfter1Year : 0))))))"
      },
      {
        "path": "$.daysEntitled",
        "expr": "(qualifies = true ? $const.baseDays + addedDays : 0)"
      },
      {
        "path": "$.daysRemaining",
        "expr": "($r := daysEntitled - $n(daysTaken); $r < 0 ? 0 : $round($r, 1))"
      }
    ],
    "constraints": [],
    "viewDefinition": {
      "renderer": "builtin",
      "defaultView": "main",
      "views": [
        {
          "id": "main",
          "label": "年次有給休暇",
          "layout": "vertical",
          "components": [
            {
              "id": "note",
              "type": "staticText",
              "text": "Article 39(1) gives “十労動日” — ten working days — but only after “六箇月間継続勤務し全労動日の八割以上出勤した”: six months of continuous service AND attendance on at least 80% of all working days. Both conditions, and the attendance test is a gate rather than a reduction — at 79% the entitlement is not smaller, it is nothing."
            },
            {
              "id": "inputs",
              "type": "fieldSet",
              "label": "あなたの勤続",
              "components": [
                {
                  "id": "serviceMonths",
                  "type": "numericField",
                  "label": "Months of continuous service",
                  "bind": "$.serviceMonths",
                  "helperText": "Counted from your hire date. The table in art. 39(2) then steps by each year AFTER the six-month mark."
                },
                {
                  "id": "attendanceRate",
                  "type": "numericField",
                  "label": "Attendance as a % of all working days",
                  "bind": "$.attendanceRate",
                  "helperText": "The 80% test in art. 39(1). Below it, art. 39(2)'s proviso means no leave need be granted for that year at all."
                },
                {
                  "id": "daysTaken",
                  "type": "numericField",
                  "label": "Days already taken",
                  "bind": "$.daysTaken"
                }
              ]
            },
            {
              "id": "sep",
              "type": "separatorLine"
            },
            {
              "id": "entitledTile",
              "type": "statTile",
              "label": "Paid leave days",
              "value": "$.daysEntitled"
            },
            {
              "id": "remainingTile",
              "type": "statTile",
              "label": "Days remaining",
              "value": "$.daysRemaining"
            },
            {
              "id": "breakdown",
              "type": "keyValueList",
              "label": "How that is worked out",
              "items": [
                {
                  "label": "Base, art. 39(1)",
                  "value": "$.daysEntitled"
                },
                {
                  "label": "Years past the six-month mark",
                  "value": "$.yearsAfterQualifying"
                },
                {
                  "label": "Added by art. 39(2)'s table",
                  "value": "$.addedDays"
                }
              ]
            },
            {
              "id": "assumptions",
              "type": "staticText",
              "text": "The table in art. 39(2) adds 1, 2, 4, 6, 8 and 10 working days at one through six years past the six-month mark, and stops there — “六年以上”, six years or more, so twenty days is the statutory ceiling however long you stay. Art. 39(3) provides a proportional entitlement for short-week employees, but the figures are set by Ministry of Health, Labour and Welfare ordinance rather than by the Act, so this page does not assert them. Nor does it model art. 39(4)'s hourly leave or the five-day designated-leave duty in art. 39(7)."
            },
            {
              "id": "sources",
              "type": "sourceList",
              "label": "出典",
              "layers": 1,
              "items": [
                {
                  "label": "労働基準法 第三十九条 — e-Gov (Labour Standards Act art. 39: the ten days, the six-month and 80% conditions, and the service-year table)",
                  "url": "https://laws.e-gov.go.jp/law/322AC0000000049",
                  "date": "2026-10-11",
                  "covers": [
                    "baseDays",
                    "qualifyingMonths",
                    "attendancePercent",
                    "bandYear1",
                    "addAfter1Year",
                    "bandYear2",
                    "addAfter2Years",
                    "bandYear3",
                    "addAfter3Years",
                    "bandYear4",
                    "addAfter4Years",
                    "bandYear5",
                    "addAfter5Years",
                    "bandYear6",
                    "addAfter6Years"
                  ]
                }
              ]
            }
          ]
        }
      ]
    },
    "tests": [
      {
        "description": "K1 under six months there is no entitlement at all",
        "given": {
          "$.serviceMonths": 5,
          "$.attendanceRate": 100,
          "$.daysTaken": 0
        },
        "expect": {
          "$.qualifies": false,
          "$.daysEntitled": 0
        }
      },
      {
        "description": "K2 at six months exactly, art. 39(1)'s ten working days",
        "given": {
          "$.serviceMonths": 6,
          "$.attendanceRate": 100,
          "$.daysTaken": 0
        },
        "expect": {
          "$.qualifies": true,
          "$.yearsAfterQualifying": 0,
          "$.daysEntitled": 10
        }
      },
      {
        "description": "K3 one year past the six-month mark adds one day",
        "given": {
          "$.serviceMonths": 18,
          "$.attendanceRate": 100,
          "$.daysTaken": 0
        },
        "expect": {
          "$.yearsAfterQualifying": 1,
          "$.addedDays": 1,
          "$.daysEntitled": 11
        }
      },
      {
        "description": "K4 the table is not linear: three years past adds four days, not three",
        "given": {
          "$.serviceMonths": 42,
          "$.attendanceRate": 100,
          "$.daysTaken": 0
        },
        "expect": {
          "$.yearsAfterQualifying": 3,
          "$.addedDays": 4,
          "$.daysEntitled": 14
        }
      },
      {
        "description": "K5 six years past the mark is the statutory ceiling of twenty",
        "given": {
          "$.serviceMonths": 78,
          "$.attendanceRate": 100,
          "$.daysTaken": 0
        },
        "expect": {
          "$.yearsAfterQualifying": 6,
          "$.addedDays": 10,
          "$.daysEntitled": 20
        }
      },
      {
        "description": "K6 and it plateaus: thirty years' service is still twenty days",
        "given": {
          "$.serviceMonths": 360,
          "$.attendanceRate": 100,
          "$.daysTaken": 0
        },
        "expect": {
          "$.daysEntitled": 20
        }
      },
      {
        "description": "K7 the 80% attendance test is a gate, not a reduction: 79% is nothing",
        "given": {
          "$.serviceMonths": 78,
          "$.attendanceRate": 79,
          "$.daysTaken": 0
        },
        "expect": {
          "$.qualifies": false,
          "$.daysEntitled": 0
        }
      },
      {
        "description": "K8 and 80% exactly qualifies in full — the statute says 八割以上, eight tenths or more",
        "given": {
          "$.serviceMonths": 78,
          "$.attendanceRate": 80,
          "$.daysTaken": 0
        },
        "expect": {
          "$.qualifies": true,
          "$.daysEntitled": 20
        }
      },
      {
        "description": "K9 days already taken come off the remainder, and it never goes negative",
        "given": {
          "$.serviceMonths": 78,
          "$.attendanceRate": 100,
          "$.daysTaken": 25
        },
        "expect": {
          "$.daysRemaining": 0
        }
      }
    ]
  }
}