Date Calculator — Days Between Two Dates, Add or Subtract Days & Exact Age
Work out the exact number of days between two dates, add or subtract days, weeks, months or years from any date, or find your exact age from your date of birth — in years, months and days. Everything calculates instantly in your browser. No sign-up, no data saved.
Worked example: From 1 January 2020 to 9 November 2026 is 2,504 days — that's 6 years, 10 months and 8 days, or 357 weeks and 5 days (60,096 hours). Try it above: the dates are already filled in.
Worked example: 9 November 2026 plus 30 days = 9 December 2026. It's already filled in above — change the amount or unit to try your own date.
Worked example: Born 1 January 1990, on 9 November 2026 you are 36 years, 10 months and 8 days old — that's 13,461 days lived. The dates are already filled in above.
How It Works
Days between two dates: Pick a start date and an end date. The calculator counts every calendar day between them, including leap days (29 February), then breaks the total into years, months and days, plus weeks and hours.
Add or subtract: Choose a starting date, enter an amount, pick days, weeks, months or years, and choose add or subtract. Adding months or years keeps the same day of the month where possible; if the target month is shorter (for example, 31 January plus 1 month), it lands on the last day of that month.
Exact age: Enter your date of birth and the date you want your age on (today by default). The calculator works out your age in full years, then the remaining months and days, and also shows the total number of days you have lived.
All calculations happen instantly on your device — nothing is sent to a server and no information is stored.
Frequently Asked Questions
How many days are there between two dates? Enter both dates above and the calculator shows the exact count. For example, 1 January 2020 to 9 November 2026 is 2,504 days. Leap years are counted automatically.
Does the date calculator include the end date? The total counts the days from the start date up to, but not including, the end date — the standard way of measuring a period. So from 1 January to 2 January is 1 day.
How do I add 30 days to a date? Use the "Add / Subtract Days" tab, enter your starting date and 30 days, and choose Add. For example, 9 November 2026 plus 30 days is 9 December 2026.
How is my exact age calculated? Your age in full years is counted from your date of birth, then the leftover months and days are added. Someone born 1 January 1990 is 36 years, 10 months and 8 days old on 9 November 2026.
Can I calculate my age in days only? Yes — the Age Calculator shows your total days lived as well as your age in years, months and days.
What date will it be in 6 months or 1 year? Use the "Add / Subtract Days" tab with months or years as the unit. 9 November 2026 plus 6 months is 9 May 2027, and plus 1 year is 9 November 2027.
Disclaimer: Results are estimates based on the standard Gregorian calendar. They are provided for general planning only and are not legal, medical or financial advice. Dates before 1900 or far in the future may be affected by historical calendar changes.