What is a Business Day Calculator?
A business day calculator is a tool that computes actual working days (business days) excluding weekends (Saturday, Sunday) and Korean public holidays. It accurately calculates delivery deadlines, contract terms, and administrative processing periods.
All Korean public holidays for 2025-2027 are included (New Year's Day, Lunar New Year, Independence Movement Day, Children's Day, Buddha's Birthday, Memorial Day, Liberation Day, Chuseok, National Foundation Day, Hangul Day, Christmas) along with substitute holidays. Workers' Day (May 1st) can be separately toggled on or off.
Key Features
Add/Subtract Business Days
Calculate the exact date N business days after (or before) a start date. Automatically skips weekends and holidays to give you the actual working day date.
Count Days Between Dates
Calculate the number of business days, weekends, and holidays between two dates. Useful for project duration and contract term calculations.
D-day Business Day Count
Shows the remaining business days from today to a target date in real-time. Perfect for managing deadlines and due dates.
Workers' Day Toggle
Since Workers' Day (May 1) only applies to private sector employees, government and financial institutions can exclude it from calculations.
Holiday Details
Displays a list of holidays with dates and names within the calculation period, plus upcoming holidays for reference.
How to Use
- Select Mode — Choose from 'Add/Subtract Days', 'Days Between', or 'D-day' calculation mode.
- Configure Workers' Day — Toggle whether to include Workers' Day (May 1). Include for private companies, exclude for government offices.
- Enter Dates and Days — Input the start date and number of business days (or end date / target date).
- Review Results — Check the calculated date, total calendar days, weekends/holidays count, and the holiday list.
Use Cases
Delivery & Deadline Calculation
When contracts specify 'within 10 business days', automatically calculate the exact delivery date accounting for weekends and holidays.
Administrative Processing Period
Calculate completion dates for permits, approvals, and registrations that are regulated as 'within N business days'.
Project Schedule Management
Determine the actual available working days from project start to end for resource allocation and milestone planning.
Financial/Insurance Period Calculation
Calculate business day periods for banking operations, insurance claim deadlines, and loan processing timelines.
Frequently Asked Questions
What is a Business Day Calculator?
A business day calculator computes the actual number of working days excluding weekends (Saturday, Sunday) and Korean public holidays. You can calculate the date after N business days from a start date, or count the business days between two dates.
Is Workers' Day included as a holiday?
Workers' Day (May 1st) is a paid leave day for private sector employees, not a national public holiday. Government offices, banks, and financial institutions operate normally. This calculator provides a toggle to include or exclude it.
How are substitute holidays handled?
Substitute holidays are designated when a public holiday falls on a weekend. This calculator includes all substitute holidays for 2025-2027, ensuring accurate business day calculations.
Which holidays are reflected?
All Korean public holidays are included: New Year's Day, Lunar New Year, Independence Movement Day, Children's Day, Buddha's Birthday, Memorial Day, Liberation Day, Chuseok, National Foundation Day, Hangul Day, Christmas, and substitute holidays. Workers' Day is managed via a separate toggle.
Is my data safe?
Yes, all calculations are processed in your browser and your date information is never sent to any server. No personal data is collected or stored.
Privacy Notice
This business day calculator processes all calculations in your browser. Your date information is never sent to any server, and no data is collected or stored.
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