Calculate the Exact Days Between Any Two Dates
Our days between dates calculator instantly tells you the exact number of days, weeks, months, and years between any two dates. Whether you want to know how many days until Christmas, count down to your birthday or vacation, calculate project deadlines in business days, determine your age in days, or track how long since a past event — this tool gives you precise results instantly.
Simply select your start date and end date to see a complete breakdown including total calendar days, business days (excluding weekends), full weeks, months, and years. The calculator works for any dates — past, present, or future — making it perfect for personal planning, project management, legal calculations, pregnancy tracking, and academic scheduling.
Days in Each Month: Quick Reference
| Month | Days | Cumulative Days (Standard Year) | Fun Fact |
|---|---|---|---|
| January | 31 | 31 | Named after Janus, Roman god of beginnings |
| February | 28 (29 in leap year) | 59 (60) | Only month with fewer than 30 days |
| March | 31 | 90 (91) | Start of spring in Northern Hemisphere |
| April | 30 | 120 (121) | April showers bring May flowers |
| May | 31 | 151 (152) | Named after Maia, Greek goddess of growth |
| June | 30 | 181 (182) | Summer solstice (longest day) around June 21 |
| July | 31 | 212 (213) | Named after Julius Caesar |
| August | 31 | 243 (244) | Named after Augustus Caesar |
| September | 30 | 273 (274) | Last month before Q4 begins |
| October | 31 | 304 (305) | Halloween on the 31st |
| November | 30 | 334 (335) | Thanksgiving (US) fourth Thursday |
| December | 31 | 365 (366) | Winter holidays, end of year |
Popular Date Countdowns and Historical Milestones
| Event | Date (2025) | Category |
|---|---|---|
| New Year's Day | January 1 | Holiday |
| Valentine's Day | February 14 | Holiday |
| Easter Sunday | April 20 | Holiday (varies yearly) |
| Mother's Day (US) | May 11 | Holiday |
| Father's Day (US) | June 15 | Holiday |
| Independence Day (US) | July 4 | National Holiday |
| Halloween | October 31 | Holiday |
| Thanksgiving (US) | November 27 | Holiday (varies yearly) |
| Christmas Day | December 25 | Holiday |
| New Year's Eve | December 31 | Holiday |
| Summer Solstice | June 21 | Astronomical |
| Winter Solstice | December 21 | Astronomical |
| First Day of Summer | June 21 | Season |
| First Day of Fall | September 22 | Season |
Understanding Business Days vs Calendar Days
The distinction between business days and calendar days matters for shipping estimates, legal deadlines, contract terms, financial processing, and project management. Here is what you need to know:
| Time Period | Calendar Days | Business Days | Difference |
|---|---|---|---|
| 1 week | 7 days | 5 days | 2 weekend days |
| 2 weeks | 14 days | 10 days | 4 weekend days |
| 1 month (avg) | 30 days | ~22 days | ~8 weekend days |
| 1 quarter | 91 days | ~65 days | ~26 weekend days |
| 6 months | 182 days | ~130 days | ~52 weekend days |
| 1 year | 365 days | ~260 days | ~105 weekend days |
- Shipping "3-5 business days" means Monday to Friday only — a package shipped Friday might not arrive until the following Wednesday to Friday.
- Legal deadlines in "30 calendar days" includes weekends and holidays, while "20 business days" excludes them.
- Bank processing typically refers to business days — a wire transfer taking "1-2 business days" sent on Friday may not clear until Tuesday.
- Tax filing deadlines use calendar dates, but if a deadline falls on a weekend or holiday, it extends to the next business day.
Leap Year Rules: When Does February Have 29 Days?
A leap year occurs every 4 years, adding an extra day (February 29) to keep the calendar aligned with Earth's orbit around the Sun. However, the rules have exceptions:
- 1A year is a leap year if it is divisible by 4 (2024, 2028, 2032 are leap years).
- 2EXCEPTION: Century years (ending in 00) are NOT leap years, even if divisible by 4 (1700, 1800, 1900 were NOT leap years).
- 3EXCEPTION TO THE EXCEPTION: Century years divisible by 400 ARE leap years (1600, 2000, 2400 ARE leap years).
| Leap Year | Day of Week (Feb 29) | Days in Year |
|---|---|---|
| 2024 | Thursday | 366 |
| 2028 | Tuesday | 366 |
| 2032 | Sunday | 366 |
| 2036 | Friday | 366 |
| 2040 | Wednesday | 366 |
| 2100 | N/A (NOT a leap year) | 365 |
Frequently Asked Questions
How do I calculate business days between two dates?▼
Our calculator counts total calendar days and can also show business days (Monday-Friday, excluding weekends). For precise business day calculations that also exclude public holidays, note that holiday schedules vary by country and region. Our tool counts weekdays, which is the standard business day calculation.
Does the calculator include the start and end dates?▼
By default, the calculator counts the number of days between the two dates, not including the start date but including the end date. This is the standard calculation method used in most applications. The difference between including or excluding the end date is always exactly 1 day.
How many days am I old?▼
Enter your birthdate as the start date and today as the end date to see your exact age in days. The average person reaches 10,000 days old around age 27, 20,000 days around age 54, and 30,000 days around age 82. It is a fun milestone to celebrate!
How do I count down to a future event?▼
Enter today's date as the start date and, your event date as the end date. The calculator will show you the exact number of days, weeks, and months remaining. Popular countdowns include days until Christmas, summer vacation, graduation, wedding, or a scheduled trip.
What year was I born if I am N days old?▼
Our calculator works in reverse too! Enter today's date and subtract the number of days. For reference: 10,000 days = about 27.4 years, 15,000 days = about 41.1 years, 20,000 days = about 54.8 years, 25,000 days = about 68.5 years.