DATE & TIME
Date & Time Calculators
Questions about dates look simple until a leap year, a month with 31 days or a birthday on February 29 gets in the way. These free calculators handle that for you: one finds an exact age, the other counts the time between any two dates.
Pick the tool that matches your question below. Each one runs in your browser, needs no sign-up, and shows the working behind the result.
2 calculators
Which calculator should I use?
- I want my exact age from a date of birth. Age Calculator →
- I want to know my age on a past or future date. Age Calculator →
- I want the number of days between two dates. Date Difference Calculator →
- I am counting down to an event or a deadline. Date Difference Calculator →
- I want to count the days of an event, start and end day included. Date Difference Calculator →
How these calculators work
Both calculators work with real calendar dates, including leap years, and show the steps under the result. They count every day, so weekends and public holidays are included. Months and years are not a fixed length, so any result the Date Difference Calculator gives in months or years is an approximation, while its day count is always exact.
COMMON QUESTIONS
Why does my age differ from simply subtracting the birth year?
Your age depends on whether your birthday has already happened this year. Subtracting years ignores that, so it can be one year too high. The Age Calculator compares the full dates to give the exact years, months and days.
How does a February 29 birthday work?
In years that are not leap years, a February 29 birthday is counted as a year older on 1 March. Some legal systems use 28 February instead, so check the official rules if it matters.
Can I calculate an age on a past or future date?
Yes. Use the "Calculate as of" date to find an age on any date after the birth date, for example for a form, a school cut-off or a milestone birthday.
What is the difference between the Age Calculator and the Date Difference Calculator?
The Age Calculator starts from a date of birth and gives years, months and days. The Date Difference Calculator works between any two dates and gives total days, weeks and approximate months, which suits countdowns, projects and trips.
When should I tick "Include the end date"?
Tick it to count every calendar day involved, such as a 5-day event running from the 1st to the 5th. Leave it unticked for the gap or the number of nights, such as a hotel stay or the days remaining until a deadline.
Does the Date Difference Calculator count working days?
No. It counts every calendar day, including weekends and public holidays. For business days, subtract the weekends and holidays yourself, or treat the result as an upper limit.
Why are months and years only approximate in the Date Difference result?
Months range from 28 to 31 days, so there is no single exact conversion from days. The calculator uses average lengths and rounds down, while the day count itself is always exact.
Is my date of birth stored or sent anywhere?
No. The calculations run in your browser and nothing you enter is sent to a server.