Date Tools
Free date calculators that run in your browser. Pick a tool below — nothing you enter is sent or stored.
Last updated: 8 November 2026
- Date calculatorDays between dates and add or subtract days, on one page.
- Days between datesExact days, weeks and months between two dates.
- Add days to a dateAny date plus or minus a number of days.
- 30 days from todayAlso 90, 100 and 180 days.
- Age calculatorAge in years, months and days, plus your next birthday.
- Day of the weekWhat day was I born? Any date, past or future.
- Business daysWorking days with UK, US or Singapore holidays.
- Week numberCurrent ISO week and all 2027 weeks.
- Chinese zodiacYour animal by birth date, 1924–2031.
- Full moon calendarNext full moon and every full moon in 2026–2027.
Which tool should I use?
Counting a gap between two dates — a trip, a pregnancy, the time since an event — use days between dates. Finding a deadline such as a return window, a notice period or a visa limit, use add days to a date; the fixed pages for 30, 90, 100 and 180 days show the answer straight away. If weekends and public holidays should not count, use the business days calculator.
For people rather than deadlines, the age calculator gives an exact age and the days to the next birthday, the day of the week calculator tells you whether you were born on a Monday or a Saturday, and the Chinese zodiac calculator handles January and February birthdays correctly by using the actual date of Chinese New Year.
How the tools calculate
All tools use the Gregorian calendar and count whole calendar days at midnight in your own time zone, so daylight saving changes never add or remove an hour from the result. Details are on how we calculate dates.
Frequently asked questions
- Are the tools free?
- Yes. Every tool is free and needs no sign-up.
- Do the tools work offline?
- Once a page has loaded, the calculator keeps working without a connection.
- Is my date of birth stored?
- No. Calculations run in your browser and nothing is sent to a server.