Days between dates calculator
Calculate the number of days, weeks, months and working days between two dates. Free online date difference calculator.
Date and Time Calculators
Date and Time Calculators
Date and time calculators answer the questions that come up every day: exactly how old am I, how many days until a deadline, how many working days fall between two dates excluding public holidays. All tools run in the browser, are free and require no login.
Date operations (4)
New New Add or subtract days from a date
Add or subtract any number of days, weeks or months from a date. Free online date calculator — instantly find the resulting date for any deadline.
Date and Time CalculatorsNew Week number calculator (ISO 8601)
Find the ISO 8601 week number for any date. Enter year, month and day — the calculator returns the week number, ISO year and day of the week instantly. Free.
Date and Time CalculatorsNew Countdown calculator — days until any date
Calculate how many days, hours, minutes and seconds remain until any date. Enter your target date and the countdown calculator gives an instant result. Free, no signup.
Date and Time Calculators
Age and work (4)
Popular Age calculator
Calculate your exact age in years, months and days. Find out how many days until your next birthday. Free age calculator.
Date and Time CalculatorsNew Working days calculator
Calculate the number of working days in a month or in the year 2026. The tool accounts for Polish public holidays and returns the result instantly.
Date and Time CalculatorsNew Polish vacation days calculator
Find out how many vacation days you are entitled to in Poland. Enter your total years of service and the calculator instantly shows 20 or 26 days per Polish Labour Code.
Date and Time CalculatorsNew Poland work hours calculator 2026
Calculate nominal working hours for any month or full year in Poland 2026. Accounts for all public holidays under the Labour Code Art. 130. Free, instant results.
Date and Time Calculators
Dates and time — what the calculators can do
Age calculator. The most common time question is "how old am I?" — but the precise answer includes not just years, but also months and days. The age calculator takes a date of birth and a reference date (today by default) and returns the result in full years, months and days. It is useful for filling in medical or insurance forms, and for parents tracking a young child's age in months for the paediatrician. You can also enter any historical date as the reference point to find out how old you were at a particular moment. Date difference. The date difference calculator counts exactly how many days, weeks, months or years separate two chosen dates. This is indispensable wherever a precise time interval matters: calculating the duration of a tenancy, the remaining warranty period, the length of a project, or an employee's length of service. Results can be shown as a total number of days or broken down into years, months and remaining days. Adding and subtracting days. When you need to find out what date falls 30 or 90 days from today, the date calculator does it instantly. The subtract option lets you go back in time — for example, to find a purchase date from a warranty expiry. The calculator handles leap years and correctly accounts for months of different lengths. Working days calculator. Not every day between two dates is a working day. The working-days calculator subtracts weekends and Polish public holidays: New Year (1 Jan), Epiphany (6 Jan), Easter Sunday and Easter Monday (moveable), Labour Day (1 May), Constitution Day (3 May), Corpus Christi (moveable), Assumption of Mary (15 Aug), All Saints' Day (1 Nov), Independence Day (11 Nov), and Christmas (25–26 Dec). The result is essential for correctly computing statutory deadlines, invoice payment terms and holiday entitlement. Payment deadline and countdown. The payment deadline calculator shows the exact due date for an invoice with a term of, for example, 14, 30 or 60 days from the issue date. The day-counter shows how many days (and optionally hours) remain until a chosen event — an exam, a trip, a document submission deadline. Both features can count working days only, skipping weekends and public holidays. Day of week and leap year. The day-of-week calculator returns the weekday for any date — past or future. This is useful for scheduling events or reconstructing historical timetables. A leap year has 366 days instead of 365: a year is a leap year if it is divisible by 4 but not by 100, unless it is also divisible by 400. The year 2024 was a leap year; 2100 will not be. All date calculators on Liczbnik are free, run in the browser without registration, and keep Polish public holiday data up to date.
Frequently asked questions about date calculators
How do I calculate my exact age in years, months and days?
Enter your date of birth into the age calculator. It subtracts your birthdate from today's date and returns the result broken down into full years, complete months and remaining days. You can also set a custom reference date instead of today.
How do I count the number of days between two dates?
The date difference calculator subtracts the earlier date from the later one and returns the result in days. It can also express the difference in weeks, months or years. Useful for tenancy periods, warranty durations and project timelines.
How do I calculate working days between two dates?
The working-days calculator removes all weekends and Polish statutory public holidays from the total. The result is the number of actual business days — essential for statutory deadlines and invoice terms. Easter and Corpus Christi are included as moveable holidays.
What is a leap year and how do I identify one?
A leap year has 366 days, with 29 February added. The rule: a year is a leap year if divisible by 4, but not by 100, unless it is also divisible by 400. So 2024 was a leap year; 2100 will not be.
How do I calculate an invoice payment deadline?
Enter the invoice issue date and the payment term in days (e.g. 14, 30 or 60). The calculator adds the exact number of days and gives you the due date. You can optionally shift the result to the next business day if the due date falls on a weekend.
How many days does each month have?
January, March, May, July, August, October and December have 31 days. April, June, September and November have 30 days. February has 28 days in a regular year and 29 in a leap year.
How do I add or subtract days from a date?
Enter a starting date and the number of days to add or subtract. The calculator returns the resulting date, correctly handling months of different lengths and leap years. Useful for finding delivery dates, expiry dates or historical reference points.
How do I find the day of the week for any date?
The day-of-week calculator accepts any date and returns the weekday name. It works for past and future dates and is handy for planning meetings, reconstructing schedules or checking on which day a public holiday falls.
How many weeks are in a year?
A calendar year has 52 full weeks plus 1 or 2 extra days. In a leap year there are 52 weeks and 2 extra days. ISO week numbers start on Monday and can reach 53 in certain years.
How do I calculate age in months — for example for a baby?
The age calculator can display the result as total months or total days, not just full years. Age in months is the standard measure used in paediatrics and vaccination schedules for infants and toddlers.