How the Hong Kong paid annual leave calculator is verified

Inputs

Input	Field	Type
Years of service under a continuous contract	`serviceYears`	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)
Completed Years	`completedYears`	`$floor($n(serviceYears))`
Days Entitled	`daysEntitled`	`($y := completedYears; $y < $const.qualifyingYears ? 0 : ($y <= $const.bandYear2 ? $const.daysYears1to2 : ($y = $const.bandYear3 ? $const.daysYear3 : ($y = $const.bandYear4 ? $const.daysYear4 : ($y = $const.bandYear5 ? $const.daysYear5 : ($y = $const.bandYear6 ? $const.daysYear6 : ($y = $const.bandYear7 ? $const.daysYear7 : ($y = $const.bandYear8 ? $const.daysYear8 : $const.daysYear9Plus))))))))`
Days Remaining	`daysRemaining`	`($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
`daysYears1to2`	7
`daysYear3`	8
`daysYear4`	9
`daysYear5`	10
`daysYear6`	11
`daysYear7`	12
`daysYear8`	13
`daysYear9Plus`	14
`bandYear2`	2
`bandYear3`	3
`bandYear4`	4
`bandYear5`	5
`bandYear6`	6
`bandYear7`	7
`bandYear8`	8
`bandYear9`	9
`qualifyingYears`	1

Test vectors (11)

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 under a year there is no entitlement yet

given `serviceYears`	0
given `daysTaken`	0
expect `daysEntitled`	0

Case 2 — N2 the first year gives 7

given `serviceYears`	1
given `daysTaken`	0
expect `daysEntitled`	7

Case 3 — N3 the SECOND year also gives 7 — the table does not step yet

given `serviceYears`	2
given `daysTaken`	0
expect `daysEntitled`	7

Case 4 — N4 the third year is the first increase, to 8

given `serviceYears`	3
given `daysTaken`	0
expect `daysEntitled`	8

Case 5 — N5 the fifth year is 10

given `serviceYears`	5
given `daysTaken`	0
expect `daysEntitled`	10

Case 6 — N6 the eighth year is 13

given `serviceYears`	8
given `daysTaken`	0
expect `daysEntitled`	13

Case 7 — N7 nine years reaches the maximum of 14

given `serviceYears`	9
given `daysTaken`	0
expect `daysEntitled`	14

Case 8 — N8 and it stays at 14 thereafter

given `serviceYears`	30
given `daysTaken`	0
expect `daysEntitled`	14

Case 9 — N9 a part year does not move the band

given `serviceYears`	4.9
given `daysTaken`	0
expect `completedYears`	4
expect `daysEntitled`	9

Case 10 — N10 days already taken come off the remainder

given `serviceYears`	9
given `daysTaken`	5
expect `daysRemaining`	9

Case 11 — N11 taking more than the entitlement never goes negative

given `serviceYears`	1
given `daysTaken`	40
expect `daysRemaining`	0

Sources

Labour Department, The Employment Ordinance Cap. 57 — paid annual leave (7 days after every 12 months, rising by the stated table to 14 from the ninth year) · 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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