Public Holiday Calendar Setup: Effect on Timesheets

Why the holiday calendar is more than a list of dates

Setting up the public holiday calendar in HR looks like a minor chore in most companies: someone types up a list in January, enters it once, and forgets about it. In practice, that calendar quietly decides how every timesheet and overtime calculation behaves for the rest of the year. If a holiday is missing from the calendar, an employee who works that day gets treated as if it were an ordinary shift, and the extra holiday pay never enters the calculation. If a day is wrongly marked as a holiday, the opposite happens: an off-site violation alert fires for someone who simply wasn't scheduled to work, and a false alarm lands on a manager's desk for no reason.

This piece looks at what the rules around public holidays actually require, how to configure the calendar in practice, and how it feeds into timesheets and overtime pay.

What counts as a public holiday, and why dates move

In Turkey, national and religious holidays are set out in Law No. 2429 on National Holidays and General Holidays. These split into national day, official holiday (dates like April 23, May 19, August 30) and general holiday (January 1, May 1, religious holidays, New Year's Eve). Article 47 of the Labour Law requires full pay on these days even when no work happens, and an additional day's wage on top of that when the employee does work.

Two details trip people up every year:

• Religious holiday dates shift annually. Ramadan and Eid al-Adha follow the lunar calendar, so their Gregorian dates move each year. Enter the calendar once and leave it alone, and it's wrong by the following year without anyone noticing until payroll runs.
• Half-day holidays need their own treatment. The afternoon before a religious holiday is typically treated as a holiday from roughly 1pm onward, not the whole day. Mark it as a full day and the morning shift gets misclassified along with it.

If your company has contractual or collective-agreement terms layered on top of the statutory minimum, confirm them with an accountant or legal counsel before configuring the calendar — this article isn't a substitute for that advice.

How the calendar drives the timesheet

In companies running field teams, the timesheet isn't a spreadsheet someone fills in anymore — it's generated automatically overnight from actual check-in and check-out activity. For that automatic generation to be correct, the system needs an unambiguous answer to "is today a normal working day or a public holiday?" In HR-Tech, working hours and the public holiday calendar sit on the same settings screen, and the timesheet engine classifies every day against it.

The most visible effect shows up in alerting: out-of-site violations are only raised within defined working hours, and approved off-site duty and public holidays are exempt from that check. When the calendar is missing an entry, an employee sitting at home on a holiday can trigger an "outside the site" warning — not a system bug, just noise from incomplete data. That same noise undermines shift calendar planning, because a manager now has to sort real violations from false ones before trusting the alert at all.

Overtime and holiday work: how it flows into the calculation

Under Turkish labour law, an employee who works on a public holiday is owed the regular day's wage plus an additional day's wage — a different calculation from standard overtime, and one that payroll needs to see as its own line item, not folded into a generic overtime bucket. When the calendar is configured correctly, the system automatically tags that day's recorded hours as "holiday work," and that tag survives the handoff to payroll or an ERP.

That handoff typically runs one of two ways: a signed webhook that fires the moment the event happens, or a read-only REST API that payroll pulls from on a schedule. We covered the tradeoffs between webhooks and API integration in more detail elsewhere; for exception cases like holiday work, which method you pick determines whether payroll has to manually flag these records a second time or not.

Setting up the calendar, step by step

1. Enter the full year's holidays ahead of time. Fixed-date official holidays only need entering once; religious holidays need updating every year against the official calendar once dates are published.
2. Mark half-day holidays separately. Treat the afternoon before a religious holiday as a holiday from the correct cutoff time, not the full day — otherwise that morning's shift gets misclassified.
3. Check for branch-level differences. Companies operating across multiple provinces may have local observances that don't apply everywhere; a single national calendar won't fit every branch.
4. Cross-check against the shift plan. After entering the calendar, open that week's shift plan and confirm the holiday days show up correctly.
5. Compare against last year's data. Checking last year's holiday timesheet records against this year's setup is the most reliable way to catch a day you forgot to add.

Common mistakes

• Entering the calendar once and never revisiting it. Because religious holiday dates move every year, a calendar carried over unchanged is wrong by definition the second year.
• Skipping local observances. Focusing only on national holidays and missing provincial ones produces wrong timesheets for employees at that branch.
• Marking half-days as full days. Treating a holiday-eve morning as non-working time causes problems in both payroll and employee trust.
• Updating the calendar after the timesheet period has already closed. A correction made after month-end means recalculating that month's reports; preparing next year's calendar every January removes that risk entirely.

The takeaway

The public holiday calendar is an invisible rule that runs every single day: it decides which days the timesheet treats as normal and which as exceptions, it cuts down on false off-site alerts, and it makes sure payroll gets the right data without a manual patch. Set it up carefully once, update it every January, and the small recurring errors stop recurring.

In HR-Tech's field-tracked HR platform, working hours and the public holiday calendar live on the same settings screen, and timesheets are generated against that calendar automatically — you can see the product in more detail on the HR-Tech page. If you'd like to walk through your calendar setup or your current timesheet process together, reach out through our contact page.