Counting days between dates answers one specific, common question: exactly how many days separate two given dates? This page covers how to count days between two dates accurately (including a detail that trips up manual counting), a quick reference for how many days are in each month, and how to find the number of days until a specific upcoming date. Browse all calculators if you need a different tool, or use the age calculator for years, months, and days from a birth date.
How to Count Days Between Two Dates
The Basic Day-Count Method
Counting days between two dates means finding the total number of calendar days that separate them — accounting for the varying length of each month (28, 29, 30, or 31 days) and leap years along the way, rather than a rough estimate.
Inclusive vs. Exclusive Day Counting
Why the Count Might Be Off by One
One detail that causes confusion in manual day counting: whether both the start and end date should be included in the total. An exclusive count (this calculator's default) counts only the days between the two dates, not the start date itself. An inclusive count adds one extra day, counting both the start and end date — this matters for things like counting the total length of a rental period or an event, where both endpoints are typically meant to count toward the total. A toggle for inclusive counting is available for exactly this situation.
How Many Days in a Given Month
Days in August, September, and Other Months
A quick reference for how many days are in each month:
| Month | Days |
|---|---|
| January | 31 |
| February | 28 (29 in a leap year) |
| March | 31 |
| April | 30 |
| May | 31 |
| June | 30 |
| July | 31 |
| August | 31 |
| September | 30 |
| October | 31 |
| November | 30 |
| December | 31 |
August has 31 days and September has 30 — a common source of small counting errors when working out a date range by hand across a month boundary, since not every month follows the same length.
Days Until a Specific Date
Example: How Many Days Until May 21
Counting days until a specific future date (like May 21) works the same way as counting between any two dates — entering today's date and the target date returns the exact number of days remaining, which is useful for countdowns to events, deadlines, or any date being planned around.
Two Weeks Today and Other Quick References
Example: Two Weeks From Today
"Two weeks today" refers to the date exactly 14 days from now — a common shorthand reference point for scheduling appointments, deadlines, or follow-ups a standard two-week interval out. This calculator's day-counting logic supports checking this kind of quick reference by entering today's date and 14 days as the target span.
For adding or subtracting a specific number of days or months from a date (like "6 months from today" or "31 days from today"), see the note below — that's handled by a related but distinct calculation.
Worked Examples: Counting Days Between Real Dates
Example: 30 Days Between Two Given Dates
Between March 1 and March 31 (exclusive counting, not including March 1 itself), there are exactly 30 days — even though the span looks like it should be 31, since March has 31 days, exclusive counting doesn't count the starting day itself. With inclusive counting turned on, the same span would show 31 days, since both endpoints would then be counted.
Adding or Subtracting Time From a Date
This calculator is specifically built to count the days between two dates you provide. For the related but different task of adding or subtracting a specific number of days, weeks, months, or years from a single starting date — like finding what date is 6 months from today, 31 days from today, or 18 months from a given date — the date difference calculator has a dedicated "Add or Subtract From a Date" mode built for exactly that.
Frequently Asked Questions
How do I count the days between two dates?
Enter both dates, and the calculator returns the exact number of days between them, accounting for varying month lengths and leap years.
What's the difference between inclusive and exclusive day counting?
Exclusive counting counts only the days between the two dates, not the start date. Inclusive counting adds one extra day, counting both the start and end date.
How many days are in August?
August has 31 days.
How do I find how many days until a specific date, like May 21?
Enter today's date and the target date, and the calculator returns the exact number of days remaining until that date.
What does two weeks today mean?
It refers to the date exactly 14 days from today, commonly used as a scheduling reference point.
Can this calculator add or subtract days from a date?
This tool focuses on counting days between two given dates. For adding or subtracting days, weeks, or months from a single date, the date difference calculator has a dedicated mode for that.
Does this account for leap years?
Yes. Leap years are correctly factored into every day count, including February having 29 days in a leap year.
Is this days-between-dates calculator free to use?
Yes. It is free, requires no sign-up, and calculates day counts instantly.