Overview
Leave management is one of the most operationally significant HR processes a business runs — and one of the most frequently handled poorly. When it works well, employees know their entitlements, can submit requests easily, receive decisions quickly, and have a clear view of their balance at any time. Managers can approve or decline requests with full visibility of team availability. HR has accurate records, correctly accrued balances, and the reporting that payroll and compliance require.
When it does not work well, the consequences are visible across the organisation. Employees with incorrect balances — because accrual logic was applied incorrectly, because carryover was handled manually and inconsistently, because leave taken was not recorded accurately. Managers approving leave without knowing that two other team members are already out that week. HR teams managing leave disputes because the policy was not clearly communicated or consistently applied. Payroll errors because the leave balance at the end of a holiday year was not correctly reconciled.
Leave management software gives the leave process the structure, automation, and transparency that prevents these problems. Entitlements are defined in the system and applied consistently. Accrual runs automatically. Requests flow through a defined approval workflow. Balances are accurate in real time. Policy is enforced rather than communicated and hoped to be followed.
We build custom leave management systems for HR teams and operations functions that need leave management logic specific to their employment contracts, their leave policy, their approval structures, and the HR and payroll systems they work with — rather than a generic leave module that cannot represent the leave types, accrual rules, or approval workflows that apply in their organisation.
What Leave Management Software Covers
Leave type configuration. Not all leave is the same. Annual leave, sick leave, special leave, parental leave, emergency leave, unpaid leave, study leave, compensatory leave — each leave type has different entitlement rules, different accrual logic, different approval requirements, different carry-over rules, and different interactions with payroll. Leave management software that can only represent a single leave type with a single accrual rule cannot serve an organisation with a complex leave policy.
Leave type configuration defines the full parameters of each leave type — the entitlement basis (fixed annual entitlement, accrual per hour worked, accrual per period of service), the approval requirement (auto-approved, manager approval, HR approval), the carry-over rule (no carryover, limited carryover with expiry, unlimited carryover), the pay treatment (full pay, reduced pay, no pay), the maximum consecutive duration, and any restrictions (minimum notice period, blocked periods, maximum concurrent team absence).
Dutch employment law specifies minimum leave entitlements — four times the weekly working hours as the statutory minimum — and defines specific rules for sick leave, maternity leave (zwangerschapsverlof), paternity leave (geboorteverlof), parental leave (ouderschapsverlof), and the special leave categories that the Wet arbeid en zorg governs. Leave management software built for Dutch employers handles these statutory leave types correctly and ensures that statutory minimums are met before any additional contractual entitlement is applied.
Entitlement calculation. The leave entitlement for each employee depends on their contract — full-time or part-time hours, fixed or variable work pattern, length of service where entitlement scales with tenure, age-related entitlement for employees above defined age thresholds (a common feature of Dutch CAO arrangements). Entitlement calculation that is done manually or in spreadsheets is a source of errors that accumulate over time and create disputes that are difficult to resolve retrospectively.
Entitlement calculation in the leave management system derives each employee's entitlement from their contract data — reading the contracted hours, start date, and age from the HR system and applying the entitlement rules configured for the relevant employment type and CAO. Entitlement adjustments for mid-year contract changes — a full-time employee moving to part-time, or vice versa — are calculated pro-rata from the effective date of the change.
Accrual processing. Leave that is accrued rather than awarded at the start of the year — common for holiday pay in Dutch employment — accumulates period by period as the employee works. Accrual calculations run on the configured schedule, applying the accrual rate to the hours worked in the period and adding the accrued amount to the employee's balance. Accrual adjustments for absences that affect holiday accrual — sick leave beyond defined duration, unpaid leave — are applied correctly rather than requiring manual adjustment.
Request and approval workflow. The leave request workflow handles the full lifecycle of a leave request — submission by the employee, routing to the appropriate approver, decision by the approver, communication of the decision to the employee, and recording in the leave ledger. Routing rules determine who approves each request — the direct manager, a designated deputy during the manager's own absence, HR for specific leave types.
The approver's view of the request includes the context they need to make an informed decision — the employee's current balance, the team's leave calendar showing who else is already out during the requested period, any pending requests from other team members for overlapping periods, and any policy rules that apply to the requested dates (blocked periods, minimum staffing requirements). Approvals without this context produce decisions that conflict with team availability.
Approval delegation — automatic reassignment of approval responsibility when the primary approver is themselves on leave — prevents requests from waiting indefinitely for an approver who is not available to process them.
Balance management. Leave balances are the cumulative record of entitlement, accrual, and usage. Balance accuracy is fundamental to leave management — an employee cannot manage their own leave, and HR cannot manage the organisation's leave liability, without accurate balances.
Balance calculations handle the full complexity of real-world leave management: entitlement awarded at the start of the leave year or accrued through it, leave taken deducted from the correct balance component (statutory before contractual, in the order that Dutch employment law requires), carry-over applied at year end with expiry dates on carried-over balances, accrual additions applied as they occur.
Balance visibility — employees see their current balance broken down by entitlement component, with carried-over and current-year balances shown separately — eliminates the leave balance enquiries that consume HR time when employees do not have direct access to accurate balance information.
Holiday year processing. The transition from one holiday year to the next requires the year-end processing that ensures balances are correctly carried over or expired. Year-end processing calculates the carry-over for each employee — applying the carry-over limits configured for each leave type, expiring the statutory minimum leave that cannot be carried over beyond the statutory expiry date (1 July following the accrual year in Dutch law), and opening the new-year balances. Year-end processing that is automated and auditable replaces the manual spreadsheet exercise that this process otherwise requires.
Absence recording and sick leave management. Sick leave requires specific handling beyond standard leave management — the Dutch reintegration obligation (two-year sick pay obligation under the Wet verbetering poortwachter), the interaction between sick leave and holiday accrual, and the reporting obligations to the UWV for long-term sick leave. Absence recording in the leave management system tracks sick leave durations, triggers the case management workflow for absences that exceed defined thresholds, and provides the absence data that the reintegration file (re-integratieverslag) and UWV reporting require.
Reporting. Leave management data that is only accessible through individual employee records cannot drive the operational insights that HR and management need. Leave reporting surfaces the patterns and totals that inform workforce planning and policy management:
Leave utilisation by team, department, and organisation — identifying teams with unusually high or low leave utilisation that may indicate workforce planning issues. Absence rates and sick leave frequency — identifying absence patterns that may indicate employee wellbeing issues or attendance management requirements. Carry-over liability — the financial liability represented by unused leave balances that will carry forward to the next year. Leave liability on termination — the accrued but untaken leave that must be paid out on employment termination. Blocked period compliance — whether leave approvals have inadvertently breached minimum staffing requirements during defined critical periods.
Dutch Employment Law Compliance
Leave management in Dutch employment operates within a specific legal framework that leave management software built for Dutch employers needs to handle correctly.
Statutory leave minimum. The Dutch statutory minimum leave entitlement is four times the weekly contracted hours — 20 days for a full-time employee on a five-day week. The statutory minimum must be fulfilled before contractual additional leave is consumed, and the statutory minimum carries specific expiry rules (expires 1 July following the accrual year) that differ from contractual leave carry-over rules.
Zwangerschapsverlof en geboorteverlof. Maternity leave (minimum 16 weeks, partially before and partially after the expected delivery date) and paternity/partner leave (geboorteverlof — 5 days, plus the extended geboorteverlof of up to 5 weeks partially funded through UWV) have specific duration rules, notification requirements, and interactions with other leave types that need to be handled correctly.
Ouderschapsverlof. Parental leave — 26 weeks at reduced pay under the Wet betaald ouderschapsverlof, with the first 9 weeks funded through UWV — has specific eligibility rules, request notification requirements, and the interaction with the UWV reimbursement process that leave management software needs to track.
CAO-specific provisions. Collective labour agreements (CAOs) frequently add to the statutory leave framework — additional leave entitlement, age-related leave, service-related leave, special leave categories. Leave management software that handles CAO-specific provisions without requiring custom code changes for each CAO allows the system to be configured rather than modified when the applicable CAO changes.
Integration Points
AFAS. AFAS is the primary HR system for many Dutch employers. Leave management integrated with AFAS reads employee data — contracted hours, start date, employment type, applicable CAO — from AFAS as the source of truth and writes leave requests, approvals, and balance updates back to AFAS so that the leave record in AFAS stays current. For organisations using AFAS for payroll, the leave balance data that AFAS needs for holiday pay calculations is kept accurate through the integration.
Exact Online. Leave liability data — the financial value of accrued but untaken leave — fed to Exact Online for the balance sheet provision that accounting standards require. Leave costs by cost centre for management reporting.
Payroll processors. Leave balance data at payroll cutoff — the basis for holiday pay calculations in Dutch payroll — provided to the payroll processor in the required format and at the required timing.
Calendar systems. Approved leave published to the employee's calendar — Google Calendar, Outlook — and to shared team calendars so that absence is visible in the calendar infrastructure the organisation uses for scheduling.
Technologies Used
- React / Next.js — leave request interface, employee balance views, manager approval dashboard, HR reporting
- TypeScript — type-safe frontend and API code throughout
- Rust / Axum — leave calculation engine, accrual processing, balance computation at scale
- C# / ASP.NET Core — AFAS and Exact Online integration, payroll data feeds, complex Dutch employment law logic
- SQL (PostgreSQL, MySQL) — leave ledger, accrual history, request records, balance snapshots
- Redis — workflow state, notification queuing, calendar sync coordination
- AFAS — employee data source and leave record synchronisation
- Exact Online — leave liability financial data
- Google Calendar / Outlook — approved leave calendar integration
- SMTP / SMS — request notifications, approval communications, balance alerts
- REST / Webhooks — HR and payroll system connectivity
The Spreadsheet Alternative and Its Cost
Many organisations manage leave in spreadsheets — a leave tracker that records requests, a balance calculator that applies entitlement and deductions, a calendar that shows who is out when. This approach works until it does not: until the spreadsheet formula is wrong and nobody notices, until the carry-over logic produces incorrect year-end balances, until two managers approve conflicting leave requests because they are looking at different versions of the same spreadsheet, until the payroll query about an employee's balance cannot be answered from a spreadsheet that has not been updated.
The cost of spreadsheet leave management is paid in HR administrative time, in leave balance disputes, in payroll errors, and in the legal risk of not correctly applying the statutory leave rules that Dutch employment law requires. Purpose-built leave management software eliminates these costs at a scale that justifies the investment for any organisation above a modest headcount.
Leave Management That Works for Everyone
Leave management software that works for employees — clear balances, easy requests, fast decisions — works for managers — team visibility, informed approval — and works for HR — accurate records, compliant processing, clean payroll data. These are not competing requirements. A well-built leave management system delivers all three.