How to Use the Korea Business Day Calculator
Start with the actual first and last dates of your period. The default example runs from October 8 to October 12, 2026, with both endpoints included. Select Calculate to see two working days: Thursday, October 8, and Monday, October 12. Friday is Hangul Day, Saturday is outside the default workweek, and Sunday is a public-office closure. Five calendar dates produce three distinct exclusions.
Open More to change the calendar or schedule. The default Monday–Friday pattern is a convention you can edit; it is not a claim about everyone's job. A person who works Saturdays should select Saturday as working. A company that remains open on a public holiday can add an explicit forced-open date. The holiday name stays attached to that date even when the chosen schedule treats it as available.
The start and end checkboxes are independent. If your instruction says to count after a starting date, exclude that start. If the last date is a delivery date that does not itself count toward the interval, exclude the end. Never change these choices just to match a remembered number. The displayed convention is part of the answer and must match the agreement you are trying to interpret.
Use Copy for an English sentence containing the dates, count, endpoints and source version. Under More, an audit export includes the individual dates and reasons. This makes a result easier to compare with a colleague's calendar: you can find the particular date on which the schedules disagree instead of debating two unexplained totals.
Calendar Days, Working Days and Public Holidays
A calendar day is a date in the selected civil interval. A working day is a date that survives your workweek, selected public calendar and custom closure rules. A public holiday is a status assigned by a particular jurisdiction or institution. These concepts overlap, but they do not mean the same thing. A Sunday can be both outside your workweek and a public-office closure.
The calculator handles this overlap by assigning multiple reasons to one date. It never subtracts that date twice. In the October example, Sunday can carry both a weekly-pattern reason and a public closure reason, yet it contributes one excluded date. A company closure entered for Hangul Day adds a useful annotation without creating a second lost day.
The summary uses a precedence partition so that the arithmetic reconciles. First come excluded dates outside the selected workweek. Next come public holidays that fall on an otherwise eligible weekday. Last come custom-only full-day closures. Working dates plus those three groups equal the number of admitted calendar dates. The detailed reasons remain available independently of this summary order.
A partial-day absence is different. Closing from 13:00 to 18:00 does not automatically turn the entire date into a nonworking date for day counting. In the hours calculation, that interval is removed from the selected schedule. Choose a full-day closure when the whole date should be excluded from a day-based promise; choose a partial closure when you need the remaining available hours.
What the Korean Calendar Profile Covers
The Korea option represents the public-office holiday calendar. It includes Sundays, named national and lunar holidays, applicable substitutes, dated election closures and the temporary closure recorded in the supplied historical table. It does not certify the opening hours of a bank, delivery company, shop, school or private employer. Enter that institution's own published schedule when its availability is the question.
The bundled dated Korean records cover 2025 and 2026, with an effective-law overlay for the 2026 changes. The Korea Customs Service tables supply dated holiday facts. The operative public-office holiday decree supplies the statutory scope and substitution rules. The source display retains the checked date and version rather than describing every future result as permanently current.
The 2025 institution table also lists Labor Day. That does not make it a public-office closure under the historical public-office profile used here. The engine preserves that scope distinction instead of importing every row as the same legal category. An employer can still add May 1, 2025, to its own closure template. A date's presence in a general holiday list is not sufficient evidence of a particular office's closure.
For 2027, the Korean option is an explicitly enabled current-rule projection. Future temporary designations and amendments are not knowable from a recurrence formula. A result outside the supplied source range stops with a coverage message. You may then deliberately choose weekdays only or enter your own calendar. An unavailable source is never treated as evidence that there are no holidays.
The 2026 Changes: May and July Matter
Labor Day and Constitution Day are central to comparing recent Korean working-day totals. The 2026 amendment has split commencement dates: the Labor Day change takes effect on May 1, while the amendment concerning the national-day scope takes effect on May 11. July 17 consequently belongs to the amended 2026 public-office holiday calendar. The source panel identifies this chronology rather than silently applying one timeless list.
Consider May 1 through May 8, 2026, with Monday–Friday working and both endpoints included. Labor Day removes Friday, May 1. Saturday and Sunday remove May 2 and May 3. Children's Day removes Tuesday, May 5. The remaining working dates are May 4, May 6, May 7 and May 8: four days. A list omitting Labor Day would produce a different answer.
Now count July 16 through July 20, 2026. Thursday, July 16, and Monday, July 20, are working dates. Constitution Day excludes Friday, July 17, and the weekend excludes July 18 and July 19. The answer is two. Under the historical 2025 public-office profile, July 17 is an ordinary eligible Thursday unless a custom closure applies. Updating the current rule does not rewrite that older result.
The rule-comparison control can replay an interval with the earlier 2026 amendment scope and the current effective scope. It lists the changed working classifications. That comparison is a planning diagnostic, not a separate claim that an older rule is still valid for a current deadline. Keep the source version in any saved calculation so that another person can reproduce which rule set you used.
Lunar Holidays and Substitute Days
Seollal and Chuseok use lunar-calendar dates, so their Gregorian dates move from year to year. The supplied calendar stores all three public-office holiday dates for each occasion. Counting only the central celebration date would leave out valid exclusions. For February 16 through February 20, 2026, the three Seollal dates are February 16, 17 and 18, leaving Thursday and Friday as the two working dates.
Chuseok in 2026 falls across September 24, 25 and 26. Counting September 24 through September 28 gives one working date: Monday, September 28. The Chuseok Saturday does not, by itself, create the Monday substitute that some people assume. The operative rule treats different holiday categories differently, so a blanket statement that every Saturday holiday moves to Monday is misleading.
Memorial Day provides another useful check. June 6, 2026, is Saturday. With a Monday–Friday workweek, June 6 and June 7 are excluded, but June 8 remains working in the selected public-office profile. Do not invent a Memorial Day substitute merely because the Saturday date is already outside your weekly work pattern.
Other categories have different substitution provisions. National Foundation Day falls on Saturday, October 3, 2026, and the dated calendar includes Monday, October 5, as its substitute. Buddha's Birthday falls on Sunday, May 24, and its substitute is Monday, May 25. The holiday detail identifies the original and substitute separately while the exclusion arithmetic still counts each date once.
If you need to investigate a lunar birthday rather than a closure, use the Korean lunar calendar converter. A birthday's annual conversion policy is different from the statutory public-holiday substitution rule. The anniversary calculator also keeps numbered days separate from annual calendar anniversaries. Those tools share date primitives without turning personal celebrations into public closures.
Endpoints, Reversed Ranges and Same-Day Questions
For October 8 through October 12, 2026, including both endpoints gives two working days and five calendar days. Excluding only the start leaves one working day and four calendar days. Excluding only the end also leaves one working day and four calendar days. Excluding both leaves no working dates within the three admitted calendar dates. These are different intervals, not conflicting calculations.
A same-date request needs both endpoint admissions. October 8 to October 8 counts as one calendar day and one working day when both are included. If either endpoint is excluded, the admitted interval is empty. October 9 to October 9, with both included, contains one calendar date but no working day because the selected profile marks Hangul Day as a closure.
Reversing a range keeps the start and end roles rather than silently swapping them. October 12 back to October 8 produces minus two directional working days when both endpoints are included. Its calendar-day magnitude remains five, and three unique dates are excluded. Negative direction describes moving backward through dates; it does not create a negative number of weekend dates.
Swap changes the two visible inputs deliberately. Day, month and year shortcuts also state their clamping convention. Moving one month from a date whose day does not exist in the destination month uses that month's final valid day. For an exact contractual interval, type and verify the final dates rather than assuming that a shortcut represents a special legal time-limit rule.
Adding and Rolling Working Dates
In Add mode, enter a whole signed number. The default addition excludes the start itself and advances until the requested number of eligible dates has been encountered. Adding one working day to October 8, 2026, returns October 12. Subtracting one from October 12 returns October 8. The intervening holiday and weekend are passed over because they are ineligible under the chosen settings.
The eligible-start option changes that convention. With it enabled, adding one from October 8 returns October 8 because that starting date is eligible and counts as day one. Adding one from October 9 still returns October 12 because the holiday start is ineligible. This option is especially important when someone uses a phrase such as “the first working day” rather than “one working day after.”
Adding zero returns the original date even if it is nonworking. It does not secretly roll a holiday to Monday. If you want a planning adjustment, choose Roll. Following finds the next eligible date; preceding finds the previous one. Unadjusted preserves the date. Modified following switches to the preceding eligible date when the following adjustment would leave the original calendar month; modified preceding does the reverse.
For a weekdays-only schedule, modified following moves January 31, 2026, to January 30 rather than February 2. Modified preceding moves February 1 to February 2 rather than January 30. These are explicit planning conventions. An institution's deadline policy may use a different convention or define an exception. The calculator does not determine that policy from a due-date label.
Company Closures, Recurring Rules and Reopening
Custom entries let you describe company, school, bank or personal schedules without relabelling the national calendar. Give each entry a plain label, dates and category. A range can represent a shutdown or vacation. Annual recurrence repeats the month and day labels; weekday recurrence repeats the selected weekday; monthly recurrence repeats the original day number when that label exists. Invalid civil dates are never rolled forward during import.
A custom closure on October 12 changes the October example from two working days to one. A closure on October 9 leaves the total at two because that date was already excluded. Two separately labelled October 12 entries also produce one exclusion, while their separate identifiers remain in the audit. This lets a company record overlapping reasons without losing the original information.
An explicit forced-open entry changes the working classification while retaining the public-holiday annotation. If October 9 is deliberately reopened, the example produces three working dates. Use this only for a schedule that really admits the date. Reopening a date in your planning template does not repeal a public holiday or establish a person's employment rights.
Edit, delete and undo work on the local closure collection. Saving a named schedule stores the current settings on this browser. Employee and freelance profiles are user descriptions, not preloaded labor-law packages. Export the versioned JSON backup before clearing browser data or transferring devices. Storage can be unavailable or full, so an in-memory session is still usable even when saving fails.
Working Hours, Lunch Breaks and Estimates
An eligible date with a 09:00–18:00 schedule contains nine gross scheduled hours. With a 12:00–13:00 excluded break, it contains eight working hours, or 480 minutes. The hours view keeps the gross span separate from the selected working duration. Whether a break is paid is an input assumption; the tool does not classify it under employment law.
Overlapping scheduled spans are combined before subtraction. Entering 09:00–13:00 and 12:00–18:00 creates a union of 09:00–18:00, not ten hours. Subtracting a 13:00–14:00 break leaves 480 minutes. A custom afternoon closure from 13:00 to 18:00, combined with the default noon break, leaves only 09:00–12:00: 180 working minutes on that date.
Adding three working hours from 16:00 on October 8, 2026, consumes two hours before the day's 18:00 end, skips the holiday and weekend, then consumes one hour on October 12. The target is October 12 at 10:00. Subtraction walks the selected intervals backward. These are local-schedule minutes; an international meeting with clock changes needs the Korean time converter and its explicit timezone decisions.
An entered rate of 10,000 per hour multiplied by eight selected hours gives an estimate of 80,000 before any user-defined adjustments. Decimal arithmetic avoids rounding at intermediate multiplication steps. The entered number can describe a fee or planning budget as well as wages. Overtime premiums, taxes, statutory leave and actual payroll treatment require information this simple estimate does not infer.
Comparing Korea and the United States
The US option uses the Office of Personnel Management federal holiday tables for their ordinary Monday–Friday employee scope. It does not represent every state, exchange, commercial bank or employer. An observed federal date can differ from the named holiday's calendar date, so the selected source and scope belong beside the result.
July 3 through July 6, 2026, illustrates the distinction. The Korean profile has two working dates, July 3 and July 6. The US federal profile has one, July 6, because July 3 is the observed Independence Day holiday. A joint same-date calendar also has one eligible date: it admits a date only when both selected profiles admit it.
Joint date availability is not the same as simultaneous local office hours. Friday afternoon in Seoul and Friday afternoon in New York are different instants. For a timed handoff, specify both zones and actual availability windows in the time converter. For a bank settlement, obtain the relevant banking calendar rather than assuming either national public-office calendar is sufficient.
Finding Longer Breaks with a Leave Budget
The optimizer searches the selected interval for contiguous breaks using your entered leave-day budget. It can restrict which working dates are eligible to take off. Existing holidays, weekends and full-day closures form the background schedule; the optimizer then lists the additional working dates needed for a candidate. It never assumes those dates have already been approved as leave.
Between October 8 and October 12, 2026, a one-day budget creates two four-day possibilities. Taking October 8 off yields October 8–11. Taking October 12 off yields October 9–12. Both last four dates and require one leave date. The tie rule prefers the earliest start after comparing break length and the number of leave dates, so October 8–11 appears first.
A candidate remains inside the interval you requested. Expand the range if you want the optimizer to consider a neighboring week. The bounded search accepts up to one year at a time, which keeps a visible list manageable. Its output is an explanation of a chosen schedule, not an entitlement calculation or a recommendation that a particular date is appropriate for everyone.
Exports, Private Sharing and Offline Use
CSV preserves date-level audit rows and protects text cells that could be interpreted as spreadsheet formulas. JSON preserves the request, source identity, options and result. ICS creates excluded all-day calendar events with exclusive end dates; an optional one-day alarm is controlled by the calendar app that imports it. Importing a reminder file does not guarantee background delivery on every device.
A default share link leaves out company closures and private labels. Its fragment carries the public dates and options so the recipient can recalculate. If you explicitly include custom entries, anyone with that link can read them. Check the preview choice before sending a company calendar. The embedded calculator has a separate compact, noindex surface and links back to this source guide.
Loaded calculations and bundled source tables work without a network request. Save offline is an explicit download action for the page assets already used. It does not refresh future holidays while disconnected. The source checked date remains visible, so an offline answer can be identified as a replay of a dated pack. Export backups before deleting offline packs or browser storage.
Common Mistakes and Useful Korean Terms
A frequent mistake is subtracting all holidays from a weekday total even when some fall on weekends. Use the unique-date explanation instead. Another is treating every named observance as a closure. The supplied informational examples include Jeongwol Daeboreum, Hansik, Teachers' Day and Dano; their presence in a named-day list does not make them excluded public holidays.
The glossary keeps four distinct terms visible: 공휴일 means public holiday, 대체공휴일 means substitute public holiday, 영업일 means business day, and 휴무일 means day off. Use the surrounding institution and schedule context. A learner can find related vocabulary in the Korean holiday guide and practice calendar labels through dates in Korean.
Write full ISO dates when exchanging calculation inputs. A typed date such as 05/06/2026 needs a format choice before it can be interpreted safely. The explicit-command preview also asks for clarification when “next Thursday” could mean different weeks. Confirm any closure change before it is applied, and inspect the resulting date list rather than relying on natural-language wording alone.
Use the Korea Business Day Calculator with a Dated Schedule
Keep three things with every important result: the admitted dates, the selected schedule and the source version. Together they explain why an answer is reproducible and where it may need updating. A newly designated closure can change a future plan; an older historical calculation should remain tied to the rules and dated records that applied to its own year.
Use the Korea business day calculator to do the arithmetic and expose the exclusions, then match those choices to the institution or agreement involved. When official coverage is missing, choose an explicit custom or weekdays-only plan instead of hiding the gap. Clear inputs, dated sources and one counted contribution per date make even a complicated holiday interval understandable.
Frequently Asked Questions
Does the Calculator Know Whether My Bank Is Open?
No. The Korean public-office profile describes its named public closures, while the US option describes the supplied federal holiday scope. Neither establishes an individual bank’s opening or settlement schedule. Enter the institution’s own published closures as a custom template, preserve their source, and use that selected schedule when the question concerns its availability.
Why Do Two Holiday Reasons Remove Only One Day?
Each admitted civil date is stored once with all its applicable reasons. A public holiday that overlaps a weekend or company closure therefore contributes one excluded date. The summary partitions excluded dates into weekend, weekday holiday and custom-only groups, while the audit keeps the overlapping reasons available for inspection.
Can I Calculate a Year outside the Dated Holiday Pack?
Choose weekdays only or enter a custom schedule explicitly. Exact holiday mode stops when its source coverage is missing; it never interprets a failed or unavailable source as zero holidays. Korean 2027 dates require an explicit provisional choice because they project current rules and cannot anticipate later amendments or temporary closures.
Is Adding Zero the Same as Finding the Next Working Day?
No. Adding zero preserves the starting date even when it is nonworking. Roll following is a separate operation that finds the next eligible date under the selected schedule. This distinction prevents a zero-length request from silently changing a deadline. Modified rolling also checks whether an adjustment would cross the original month.
Are Eight Working Hours a Payroll Calculation?
The selected schedule and excluded breaks determine working minutes for this planning estimate. Multiplying those minutes by your entered hourly rate produces a simple arithmetic estimate. It does not establish paid-break treatment, overtime, taxes, statutory premiums or legal entitlement. Enter and verify the schedule assumptions that apply to your particular agreement.
Will a Shared Result Reveal My Company Notes?
The default link omits custom closures and private labels, so its recipient sees public dates and options rather than the complete private company schedule. You can explicitly choose to include custom entries in the fragment. Anyone holding that expanded link can read them. Local JSON exports also contain saved settings and should be handled as private backups.
Check Your Korea Business Day Calculator Result
Recheck the two visible endpoint dates, selected calendar and source version before using a result. Keep an audit export when the calculation matters to a handoff. If the institution uses a different workweek or closure list, update that schedule explicitly and calculate again. The Korea business day calculator explains the chosen inputs; it cannot infer an unpublished agreement.