Days Between Two Dates
Select two dates to see the difference
Age Calculator
Enter your date of birth to calculate your age
Add or Subtract Days
Choose a date and number of days

Date Calculator & Age Calculator

Our free date calculator helps you quickly find the number of days between two dates, calculate your exact age down to the day, or add and subtract days from any date. All calculations happen instantly in your browser — no sign-up and no downloads. Whether you need to track project deadlines, figure out rental periods, plan an upcoming event, or simply count down to a milestone, this tool gives you accurate results with a single click.

Days Between Dates

Need to know how many days are between two dates? Enter a start date and an end date to see the exact difference in years, months, and days. The calculator also shows the total number of days, weeks, months, hours, and minutes between the two dates. This is perfect for counting down to a vacation, tracking project timelines, figuring out rental periods, or calculating the duration between any two calendar dates.

Use the "Include end date" toggle when you need to count both the start and end dates in your total — for example, a rental agreement from January 1 through January 31 is 31 days inclusive. The calculator handles leap years, varying month lengths, and even century boundaries automatically. If you only need a quick day count, check out our dedicated days between dates calculator.

Business Days vs Calendar Days

Calendar days count every day on the calendar — weekdays, weekends, and holidays alike. Business days (also called working days) only count Monday through Friday, excluding weekends and US federal holidays. The distinction matters for legal deadlines, shipping estimates, payroll calculations, and project planning.

Our date calculator lets you toggle between calendar days and business days with a single checkbox. When the "Business days only" option is enabled, weekends and all 10 US federal holidays are automatically excluded from the count. This is especially useful if you need to calculate delivery windows, payment terms (such as "Net 30 business days"), or compliance deadlines that specify working days. You can combine it with the "Include end date" toggle for full flexibility.

Age Calculator

Enter your date of birth to find your exact age in years, months, and days. The age calculator also tells you the total number of days you've been alive, which day of the week you were born on, and how many days until your next birthday. This is useful for birthday planning, verifying identification documents, or satisfying curiosity about exactly how long you've been alive.

Add or Subtract Days

Start from any date and add or subtract a specific number of days to find the resulting date. The result shows the full date, the day of the week, and whether the resulting date falls on a major U.S. holiday. Great for calculating deadlines, return dates, due dates, or any future or past date. You can also pair this with a countdown timer to track time remaining until that date arrives.

Holiday Reference

The following table lists all 10 US federal holidays used in the business-day calculation for 2026 and 2027. When the "Business days only" toggle is active, any date that falls on one of these holidays is excluded from the count.

Holiday20262027
New Year's DayJan 1 (Thu)Jan 1 (Fri)
Martin Luther King Jr. DayJan 19 (Mon)Jan 18 (Mon)
Presidents' DayFeb 16 (Mon)Feb 15 (Mon)
Memorial DayMay 25 (Mon)May 31 (Mon)
Independence DayJul 4 (Sat)Jul 4 (Sun)
Labor DaySep 7 (Mon)Sep 6 (Mon)
Columbus DayOct 12 (Mon)Oct 11 (Mon)
Veterans DayNov 11 (Wed)Nov 11 (Thu)
ThanksgivingNov 26 (Thu)Nov 25 (Thu)
Christmas DayDec 25 (Fri)Dec 25 (Sat)

Frequently Asked Questions

How do I calculate days between two dates?
Enter a start date and an end date in the "Days Between Dates" tab above. The calculator will instantly display the difference in years, months, and days, along with totals for days, weeks, months, hours, and minutes. No formula or manual counting is needed — the tool accounts for leap years, varying month lengths, and all calendar rules automatically.
Does this include the start and end date?
By default the calculator computes the gap between the two dates, which excludes the start date. For example, January 1 to January 10 returns 9 days. If you toggle "Include end date," the count becomes 10 — meaning both January 1 and January 10 are counted. This inclusive mode is useful for rental agreements, event durations, and school-day counting.
How are business days calculated?
Business days exclude Saturdays, Sundays, and the 10 US federal holidays listed in the Holiday Reference table above: New Year's Day, Martin Luther King Jr. Day, Presidents' Day, Memorial Day, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, and Christmas Day. Enable the "Business days only" checkbox to see the business-day count alongside the regular calendar-day totals.
How do I add months to a date?
Switch to the "Add/Subtract Days" tab and enter the equivalent number of days for the months you want to add. For one month you would typically add 30 or 31 days depending on the specific month. The result will show you the exact date, day of the week, and whether it falls on a US holiday. For recurring calculations, keep the tab open and update the number of days as needed.
Does this account for leap years?
Yes. Every calculation — days between dates, age, and add/subtract — correctly handles leap years. February 29 is included in leap years (2024, 2028, etc.) and omitted in common years. You will never get an incorrect count due to a missed or extra day in February.