Calculator/Date Calculator/ Date Difference Calculator
Understanding Date Calculation
Date calculation is important in various fields such as business, personal life, and law. Here are concepts you should know for accurate date calculation.
Key Terms
Weekdays: Working days from Monday to Friday
Weekends: Saturday and Sunday
Business Days: Actual working days excluding holidays
Leap Year: A year where February has 29 days (occurs every 4 years, except years divisible by 100 but not by 400)
Considerations When Calculating Dates
End Date Inclusion: Whether to include both start and end dates in the calculation
Holiday Processing: Whether to consider official holidays by country or region
Calculating a Specific Period: How to handle adding or subtracting a certain number of months or years when there is no corresponding date
Timezone Difference: Considering time zones when calculating international dates
Date Interval Calculation
Add/Subtract Date
Calculate Business Days
Find Day of Week
Calculation Results
Total Days
-
Number of Weekdays
-
Number of Weekend Days
-
Number of Business Days
-
Period Analysis
Years+Months+Days-
Months+Days-
Weeks+Days-
Hours-
Minutes-
Seconds-
Day Distribution
Start Date Information
Date
Day of Week
Day of Year
Week of Year
End Date Information
Date
Day of Week
Day of Year
Week of Year
Related Calculators
D-day Calculator
Calculates remaining days until an important date.
Generally, when calculating days in law or contracts, the principle of first day excluded, last day included is applied. For example, if its within 30 days from January 10, the period starts from January 11 (the following day, excluding January 10) and ends on February 9. However, the calculation method may differ according to the contract or law, so its important to check the relevant clauses.
When calculating business days, weekends (Saturday and Sunday) and legal holidays are typically excluded. In the case of South Korea, there are about 17 legal holidays including Lunar New Year, Chuseok festival, and national holidays. Especially since festival dates change each year, caution is needed when calculating. Additionally, due to the alternative holiday system, if a holiday coincides with a weekend, the following weekday may become a holiday, so for accurate calculation, its best to refer to the holiday calendar for the relevant year.
The date 1 month later is determined according to the number of days in the relevant month. For example, 1 month after January 15 is February 15. However, 1 month after January 31 is February 28 (February 29 in a leap year). This is because February doesnt have 31 days. This calculation method may vary according to the contract or law, so its important to check the relevant regulations when calculating important dates.