How the Malta leave tal-vaganzi calculator is verified

Inputs

Input	Field	Type
Your average weekly hours	`weeklyHours`	number
Hours in your working day	`hoursPerDay`	number
Months employed in this calendar year	`monthsWorked`	number
Public holidays falling on a Saturday, Sunday or your rest day	`holidaysOnRestDays`	number
Days already taken	`daysTaken`	number

The formula

Each derived value below is computed by the Valem engine from the expression shown, in this order. Nothing else runs — there is no hidden code path.

Derived value	Field	Formula (JSONata)
Base Hours	`baseHours`	`(($const.statutoryWeeks * $const.basisWeeklyHours + $const.extraStatutoryHours) * $n(weeklyHours) / $const.basisWeeklyHours)`
Extra Hours	`extraHours`	`$n(holidaysOnRestDays) * $n(hoursPerDay)`
Entitlement Hours	`entitlementHours`	`($m := $clampFloorCap($n(monthsWorked), 0, $const.monthsPerYear); baseHours * $m / $const.monthsPerYear + extraHours)`
Days Entitled	`daysEntitled`	`$round(entitlementHours / $n(hoursPerDay), 1)`
Days Remaining	`daysRemaining`	`($r := daysEntitled - $n(daysTaken); $r < 0 ? 0 : $round($r, 1))`

Rates and thresholds

The expressions above read these as $const. They are the figures the annual refresh replaces, so they live as data rather than being written into the formulas — which is what makes a year-on-year change a one-line diff instead of an edit to arithmetic.

Constant	Value
`statutoryWeeks`	4
`extraStatutoryHours`	32
`basisWeeklyHours`	40
`basisDailyHours`	8
`monthsPerYear`	12

Test vectors (9)

Every case is executed against this model on each build, by the Java engine and independently by a JavaScript one. A mismatch of a single cent fails the build, so the page cannot ship advertising a figure the model no longer produces.

Case 1 — N1 four weeks and thirty-two hours on a forty-hour week is 192 hours, or 24 days

given `weeklyHours`	40
given `hoursPerDay`	8
given `monthsWorked`	12
given `holidaysOnRestDays`	0
given `daysTaken`	0
expect `baseHours`	192
expect `entitlementHours`	192
expect `daysEntitled`	24

Case 2 — N2 a twenty-hour week halves the hours, and the days stay 24 on a four-hour day

given `weeklyHours`	20
given `hoursPerDay`	4
given `monthsWorked`	12
given `holidaysOnRestDays`	0
given `daysTaken`	0
expect `baseHours`	96
expect `daysEntitled`	24

Case 3 — N3 a longer week raises the hours entitlement in proportion

given `weeklyHours`	45
given `hoursPerDay`	9
given `monthsWorked`	12
given `holidaysOnRestDays`	0
given `daysTaken`	0
expect `baseHours`	216
expect `daysEntitled`	24

Case 4 — N4 three weekend public holidays add three days

given `weeklyHours`	40
given `hoursPerDay`	8
given `monthsWorked`	12
given `holidaysOnRestDays`	3
given `daysTaken`	0
expect `extraHours`	24
expect `entitlementHours`	216
expect `daysEntitled`	27

Case 5 — N5 half a year of employment halves the base, under reg. 8(4)

given `weeklyHours`	40
given `hoursPerDay`	8
given `monthsWorked`	6
given `holidaysOnRestDays`	0
given `daysTaken`	0
expect `entitlementHours`	96
expect `daysEntitled`	12

Case 6 — N6 the weekend-holiday days are added whole, not pro-rated

given `weeklyHours`	40
given `hoursPerDay`	8
given `monthsWorked`	6
given `holidaysOnRestDays`	2
given `daysTaken`	0
expect `entitlementHours`	112
expect `daysEntitled`	14

Case 7 — N7 no months employed still leaves any weekend-holiday days

given `weeklyHours`	40
given `hoursPerDay`	8
given `monthsWorked`	0
given `holidaysOnRestDays`	0
given `daysTaken`	0
expect `daysEntitled`	0

Case 8 — N8 days already taken come off the remainder

given `weeklyHours`	40
given `hoursPerDay`	8
given `monthsWorked`	12
given `holidaysOnRestDays`	0
given `daysTaken`	10
expect `daysRemaining`	14

Case 9 — N9 taking more than the entitlement never goes negative

given `weeklyHours`	40
given `hoursPerDay`	8
given `monthsWorked`	12
given `holidaysOnRestDays`	0
given `daysTaken`	40
expect `daysRemaining`	0

Sources

S.L. 452.87 Organisation of Working Time Regulations, reg. 8(1) — legislation.mt (four weeks and thirty-two hours, on a forty-hour week and an eight-hour day; adjusted where the average week differs) · checked 2026-10-11

Check it yourself — and reuse it

The whole model as JSON — inputs, outputs, formulas, vectors and sources in one re-runnable document.

This model is published under CC BY 4.0: use it, adapt it, build on it, with attribution. The licence covers the model — the expression of each rule and the arrangement of the catalog. The rates and thresholds are law, and nobody licenses those; the sources above are where they come from.

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