DeadlineDays
Calculators
No login · Browser-side calculation

SLA Deadline Calculator - Business Hours, Holidays & Time Zones

Calculate SLA deadlines from a start date and time using business hours, business days, public holidays, custom non-working days, and time zones.

No login. No database. Calculator inputs are not stored on a server.

Use this SLA deadline calculator for support response targets, incident commitments, operations handoffs, and contract planning. Choose a start time, time zone, SLA duration, business hours, non-working days, public holidays, and company holidays. The calculation runs in your browser and does not store inputs on a server.

Direct answer

4 business-hour SLA started Friday at 15:30

Example with business hours 09:00-17:00, Monday-Friday schedule, and no public holiday in the interval. Contract wording, time zone, and DST rules can change the real deadline.

Start
Fri 15:30
SLA duration
4 business hours
Business hours
09:00-17:00
Estimated deadline
Mon 11:30

Example assumptions: weekends excluded, no public holiday, start time inside business hours, same time zone throughout.

How counting works

Review how start dates, end dates, weekends, public holidays, and company holidays are applied before relying on a result.

Business Days Calculation Rules

SLA Deadline Calculator

Plan SLA response deadlines with business hours, time zones, public holidays, and calendar-hour modes.

Time zone and DST check

SLA timing is calculated as wall-clock time in the selected time zone. Confirm daylight-saving transitions, cross-region handoffs, and production service desk clock rules before using the result as an obligation.

Quick durations

Business hours

Optional. Break time is not counted inside business-hour SLA calculations.

Quick business hours

Public holiday rules can vary by state, province, region, bank, school, or organization.

Non-working days

Select the days your business or company does not work.

Load public holidays for the selected country and remove them from working days.

Enter one holiday per line, such as 2026-05-15 Company holiday or 2026-06-01.

Public holiday data

Public holiday data is loaded from the configured holiday API and may differ from official government, bank, school, employer, or carrier calendars. Verify critical deadlines with official sources.Review holiday data sources

SLA deadline calculation method

DeadlineDays interprets the selected start date and time in the chosen time zone, then counts the SLA duration according to the selected unit.

  1. Choose the start date, start time, and time zone.
  2. Choose the SLA duration and whether it is measured in business hours, business days, calendar hours, or calendar days.
  3. For business-hour mode, count only minutes inside the configured business hours.
  4. For business-day mode, convert each business day into the configured daily business-hours window.
  5. Skip selected non-working days.
  6. Skip public holidays and custom holidays when business-time mode is enabled.
  7. Calendar-hour and calendar-day modes add time directly and do not skip holidays or non-working days.
  8. If the start time is outside business hours, optionally move it to the next available business time.

Real business examples

Use these scenarios to see how the calculator supports an actual business decision, not just a date lookup.

4 business-hour support response in Asia/Seoul

Situation
4 business-hour support response in Asia/Seoul
Input assumptions
Ticket opened Thursday 15:30 KST. SLA: 4 business hours. Business hours: 09:00-17:00. Friday is a company holiday.
How DeadlineDays handles it
Count the remaining 90 minutes on Thursday, skip the Friday company holiday and weekend, then continue inside Monday business hours.
Result interpretation
Support can explain why the 4-hour response target moves to Monday morning instead of Friday.
What the user should verify
Confirm the contract time zone, DST rule, and whether company holidays are recognized by the SLA.

Ticket opened outside business hours

Situation
Ticket opened outside business hours
Input assumptions
Incident received Tuesday. SLA: three business days. Freeze day: Wednesday.
How DeadlineDays handles it
Add the freeze day as a non-working date so it does not consume one of the SLA business days.
Result interpretation
The operations team gets a response deadline that matches the internal maintenance calendar.
What the user should verify
Customer-facing SLAs may not recognize internal freeze days unless the contract says they do.

Examples

4 business-hour support response SLA

Input
Start at 10:00, use business hours 09:00-17:00, duration 4 business hours.
Output
The deadline lands at 14:00 on the same business day.

Useful for first-response support targets that pause outside working hours.

1 business-day operations deadline

Input
Start late in the day, duration 1 business day, selected non-working days are Saturday and Sunday.
Output
The calculator counts one full configured business-day window and skips the weekend if needed.

Operations teams can compare internal handoff windows without counting nights.

24 calendar-hour incident SLA

Input
Start at 16:30 and choose 24 calendar hours.
Output
The deadline is exactly 24 hours later.

Calendar mode is useful when the SLA clock runs continuously.

SLA around a weekend or public holiday

Input
Start on Friday afternoon with public holidays enabled and business-hour mode selected.
Output
The deadline skips selected non-working days and loaded public holidays.

Useful when customer support or contract obligations pause on non-working days.

Why DeadlineDays is different

The calculator pages are designed for business review, not keyword-only date content.

Country-specific public holiday data gives each calculation a concrete calendar context.
Custom non-working weekdays and company holidays support workplace-specific schedules.
Regional holiday coverage is used where reliable data is available.
Browser-side calculation, no login, and clear assumptions help users review results before copying or sharing them.
The examples stay grounded in invoices, SLA commitments, shipping promises, payroll cutoffs, and public holidays.

FAQ

What is an SLA deadline?

An SLA deadline is the date and time by which a response, resolution, handoff, or other service commitment should be completed.

What is the difference between business hours and calendar hours?

Business hours count only configured working time. Calendar hours add time continuously without skipping nights, weekends, or holidays.

Does the calculator skip weekends?

In business-hour and business-day modes, it skips the days selected as non-working days.

Are public holidays excluded?

They are excluded in business-time modes when the option is enabled and holiday data can be loaded for the selected country.

What happens if the SLA starts outside business hours?

The calculator can move the start to the next available business time before counting the SLA duration.

Can I use a custom company holiday?

Yes. Add one custom holiday per line using YYYY-MM-DD and an optional holiday name.

How are time zones handled?

The selected date and time are treated as wall-clock time in the chosen time zone and shown with that time zone label.

Is this legal, contract, payroll, or accounting advice?

No. It is a general planning tool. Confirm official SLA, contract, payroll, tax, and legal deadlines with the relevant source.

Common use cases

Use this calculator for support and operations deadlines where the clock may pause outside working hours.

Support response targets

Estimate when a response is due for P1, P2, or standard queues.

Business-hours SLA

Count only configured working hours and skip holidays when needed.

Time zone handoffs

Document the selected time zone before sharing a deadline.

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Disclaimer

This calculator is a general date and time planning tool. It is not legal, contract, accounting, payroll, tax, employment, or customer-support policy advice. Confirm real SLA obligations, contracts, support policies, statutory deadlines, and DST/time-zone boundary cases with your operating system, contract, official source, or qualified professional.