How do I calculate days between two dates?

Enter the start and end dates. The calculator counts every day between them, including leap years. Example: January 1 to March 15 in a non-leap year = 73 days. In a leap year = 74 days (February has 29 days). The calculation accounts for varying month lengths automatically.

How many business days between two dates?

Business days exclude weekends (Saturday and Sunday). A 30-day span typically contains 20-22 business days depending on how the weekends fall. To estimate: multiply weeks by 5, then add remaining weekdays. For exact counts with holidays, use a business day calculator that accounts for your country holidays.

How do I add days to a date?

Enter your start date and the number of days to add. The calculator handles month boundaries and leap years automatically. Example: January 28 + 5 days = February 2. January 28 + 35 days = March 4 (or March 3 in a leap year).

How many days are in each month?

January: 31, February: 28 (29 in leap years), March: 31, April: 30, May: 31, June: 30, July: 31, August: 31, September: 30, October: 30, November: 30, December: 31. Mnemonic: "30 days has September, April, June, and November."

A year divisible by 4, except century years unless also divisible by 400. 2024: leap year. 2025: not. 2100: not (century, not divisible by 400). 2000: leap year (century, but divisible by 400). Leap years add February 29, making the year 366 days instead of 365.

How do I calculate my exact age?

Enter your birth date and today date. The calculator gives your age in years, months, and days. It accounts for varying month lengths and leap years. Example: born March 15, 1990, on April 3, 2026 = 36 years, 0 months, 19 days.

Home / Blog / Calculator Tools

Date Calculator — Days Between Dates, Add/Subtract Days, and Age Calculator

Last updated: April 20265 min readCalculator Tools

Calculate the exact number of days between any two dates, add or subtract days from a date, or find your precise age in years, months, and days. Handles leap years, varying month lengths, and business day calculations automatically.

Common Date Calculations

From	To	Days	Weeks	Months
Jan 1	Mar 1 (non-leap)	59	8 weeks, 3 days	2 months
Jan 1	Mar 1 (leap year)	60	8 weeks, 4 days	2 months
Jan 1	Jul 1	181	25 weeks, 6 days	6 months
Jan 1	Dec 31 (non-leap)	364	52 weeks	~12 months
Today (Apr 3)	Dec 31	272	38 weeks, 6 days	~9 months
Today (Apr 3)	Jul 4	92	13 weeks, 1 day	3 months, 1 day
Today (Apr 3)	Jan 1, 2027	273	39 weeks	~9 months

Practical Date Scenarios

Scenario	How to Calculate	Example
Project deadline	Start date + business days	Mar 1 + 45 business days = May 5
Lease expiration	Start date + months	Apr 15 + 12 months = Apr 15 next year
90-day warranty	Purchase date + 90 days	Feb 10 + 90 days = May 11
Notice period	Notice date + working days	Varies by contract (30, 60, 90 days)
Countdown to event	Event date − today	Wedding: Jun 15 − Apr 3 = 73 days
Exact age	Birth date → today	Mar 15, 1990 → Apr 3, 2026 = 36 years, 19 days

Days in Each Month (Quick Reference)

Month	Days	Month	Days
January	31	July	31
February	28 / 29*	August	31
March	31	September	30
April	30	October	31
May	31	November	30
June	30	December	31

*29 days in leap years (2024, 2028, 2032...)

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Date Calculator — days between dates, add/subtract days
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Timezone Converter — convert times between zones
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Percentage Calculator — percentage of time elapsed

Calculate days between any two dates instantly — handles leap years and month boundaries.

Open Date Calculator

Date Calculator — Days Between Dates, Add/Subtract Days, and Age Calculator

Common Date Calculations

Practical Date Scenarios

Days in Each Month (Quick Reference)

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