Date Calculator
How many days until a date? What date is 90 days or 20 business days from now? Pick a mode, enter a date and get the result instantly, with the steps shown. Leave the start date empty to count from today.
How it is calculated
Three calculations in one date calculator
- Days between two dates: the difference in days, in years, months and days, and in weeks. Counting runs from day to day – 27 September to 28 September is 1 day. To count both days (for example days of a trip or of leave), tick “Include the end date”.
- Add or subtract days, weeks, months, years: days and weeks are simply counted on. For months and years the day of the month stays the same (15 November + 3 months = 15 February). If that day does not exist in the target month, the last day of the month is used: 31 January + 1 month = 28 February (29 February in a leap year), 31 January + 2 months = 31 March.
- Add or subtract business days: weekends and the public holidays of the selected country are skipped. Choose a state or region for regional holidays; without one only nationwide holidays count.
Examples
From 27 September 2026 to Christmas Eve, 24 December 2026, there are 88 days – 2 months and 27 days, or 12 weeks and 4 days. From 1 January 2026 to 24 December 2026 there are 357 days, 358 including the end date.
Business days around Thanksgiving: Wednesday, 25 November 2026 + 1 business day in the United States gives Friday, 27 November 2026 (Thanksgiving on 26 November is skipped). Around Easter in Germany (North Rhine-Westphalia): Thursday, 2 April 2026 + 1 business day = Tuesday, 7 April 2026, skipping Good Friday, the weekend and Easter Monday.
Holiday data and weekends
For more than 240 countries the public holidays come from the open-source python-holidays dataset, cross-checked against Nager.Date; only the data of the selected country is loaded. The data currently covers 2026 and 2027 – outside those years only weekends are skipped and the calculator shows a notice. German holidays are calculated from the state holiday laws for any year. The weekend depends on the country (for example Friday and Saturday in Saudi Arabia). Dates follow the Gregorian calendar as in ISO 8601.
Date calculator, time calculator or age calculator?
The date calculator works with whole calendar days. For a time span with clock times (hours, minutes, daylight saving time) use the time calculator; for someone's age from the date of birth use the age calculator.
Frequently asked questions
How many days until a date?
Choose “Days between two dates”, leave the start date empty (= today) and enter the target date. From 27 September 2026 to 24 December 2026 there are 88 days.
Is the end date included?
Not by default: counting runs from day to day, so 1 January to 2 January is 1 day. Tick “Include the end date” to count both days (2 days) – useful for trips, leave or hotel stays counted in days.
What is 31 January plus one month?
28 February, or 29 February in a leap year. If the day does not exist in the target month, the last day of that month is used. Adding two months gives 31 March again.
What date is 30 business days from today?
Choose “Add/subtract business days”, enter 30 and select your country and, if needed, your state or region. Weekends and public holidays are skipped; the start date itself is not counted.
Which years are covered for public holidays?
Germany: any year under current law. All other countries: 2026 and 2027. Outside those years only weekends are skipped and a notice is shown.
Sources and legal basis
- ISO 8601 – Date and time format (Gregorian calendar, weeks)
- python-holidays – public holiday data by country (MIT licence)
- Nager.Date – public holiday API used as cross-check (MIT licence)
As of:
Related tools
- Age CalculatorCalculate your exact age from your date of birth in years, months and days, in total days, weeks and months – plus the countdown to your next birthday.
- Time CalculatorTime duration calculator: how much time lies between two dates and times, in years, months, days, hours, minutes, seconds – plus weekdays Mon–Fri.
- Working days in Germany 2026 / 2027Working days in Germany 2026: 252 to 254 depending on the state. Calculator with all public holidays, working days per month, 5- or 6-day week, plus 2027.
- Countdown to a DateFree countdown to any date: days, hours, minutes and seconds left until your event, live and updating every second – shareable as a link or embed.
- Exponent calculator with stepsCalculate powers, nth roots and logarithms with any base – step-by-step, with negative and fractional exponents, ln, log and scientific notation.
- Fraction CalculatorAdd, subtract, multiply and divide fractions and mixed numbers with step-by-step solutions. Simplify fractions and convert decimals to fractions.