Days Between Dates
How Many Days Between Two Dates?
Whether you're counting down to an event, calculating the length of a project, determining how long someone has been employed, or figuring out how many days are left on a contract — knowing the exact number of days between two dates is one of the most common date calculations people need. This calculator gives you that number instantly, along with the breakdown in weeks, months, and business days.
How to Use This Calculator
Enter a start date and an end date — either in the past or future. Hit Calculate Days to see the total days between them, plus the equivalent in weeks, years/months/days, and an approximate business day count.
How Days Are Counted
The calculator counts from the start date up to (but not including) the end date. This is the standard convention for measuring elapsed time — a 7-day subscription starting Monday expires the following Monday (7 days elapsed, with Monday being day 0). To include both the start and end date, add 1 to the result.
The calculation accounts for leap years automatically — any February 29 between your two dates is included in the count.
Common Uses
- Countdown to an event — days until a birthday, vacation, wedding, or retirement
- Contract and lease duration — exact length of an agreement in days
- Employment tenure — how long someone has worked somewhere in exact days
- Project elapsed time — how many days have passed since a project started
- Trial period tracking — when does a 30-day or 90-day trial expire
- Legal deadlines — how many days remain before a statute of limitations or filing deadline
- Age verification — confirm exact age in days for legal or medical purposes
Business Days vs. Calendar Days
The business day estimate in this calculator assumes a standard Monday–Friday work week and does not account for public holidays (which vary by country and region). To find approximate business days: total calendar days × 5/7 ≈ business days. For a 100-day span, that's roughly 71 business days.
For legally or contractually significant business day counts that must account for specific holidays, verify against an official holiday calendar for your jurisdiction.
Reading the Results
- Total Days — the raw calendar day count
- Weeks & Days — broken into complete weeks plus remaining days (e.g., 100 days = 14 weeks 2 days)
- Years, Months & Days — a human-readable breakdown for longer spans
- Business Days (approx) — weekdays only, holidays not excluded
Frequently Asked Questions
Does this include the start date or end date in the count?
The start date is included (it's day 0), the end date is not. So from January 1 to January 8 is 7 days. If you want to count both dates as full days (inclusive counting), add 1 to the result. The right convention depends on your use case — legal deadlines typically use exclusive end-date counting.
How do I calculate days remaining until a future date?
Set the start date to today and the end date to your target date. The result shows exactly how many days remain. This is the same calculation used for countdowns — the days-between calculation is direction-agnostic and always returns a positive number.
How many days are in each month?
January (31), February (28 or 29 in leap years), March (31), April (30), May (31), June (30), July (31), August (31), September (30), October (31), November (30), December (31). A non-leap year has 365 days; a leap year has 366. This is why month-based date calculations and day-based calculations give different results.
What's the difference between this and the Date Calculator?
This calculator finds the number of days between two known dates. The Date Calculator works the opposite way — you start with one date and add or subtract a number of days (or months or years) to find the result date. Use this one when you know both dates; use the Date Calculator when you know one date and an offset.
How do I calculate someone's exact age in days?
Enter their date of birth as the start date and today (or any other date) as the end date. The total days result is their exact age in days. At 30 years old, a person has lived approximately 10,957–10,958 days (varying by leap years in their lifetime). Use our age calculator for a full age breakdown including years, months, and days.