Days Between Dates Calculator — Count Days, Weeks, Months
Count the exact number of days between two dates. Shows days, weeks, months, and hours — for project timelines, loan periods, vacations, and contract durations.
Why Use a Days Between Dates Calculator
Counting days between dates manually means tracking month lengths, leap years, and whether to include the start or end date. The calculator handles all of this — give it two dates and it returns the exact count in multiple units so you can use whichever is most useful.
- Multiple units: Days, weeks, months, hours — choose the unit that fits your use case
- Leap year accurate: February correctly handled for any year range
- Project timelines: Calculate sprint lengths, milestone gaps, and delivery windows
- Financial use: Loan periods, interest accrual windows, investment horizons
- Travel planning: Exactly how many days until your trip; how long you'll be away
- Legal and contract: Notice periods, warranty durations, probationary periods
Choose the Right Variant
- This page: Days between dates — total day count for timelines and planning
- Time Difference Calculator: Full time difference in all units
- Age Calculator: Calculate exact age from a birthdate
- Working Days Calculator: Count only business days (Mon–Fri)
- Time Until Deadline: Days and hours remaining until a future date
Step-by-Step Tutorial
- Open the Time Difference Calculator
- Enter the start date — the earlier of the two dates
- Enter the end date — the later date
- Read the result in days, weeks, or months
- To count up to and including both start and end days, add 1 to the displayed day count
Common Use Cases with Day Counts
- 30-day return window: Count from purchase date to find the exact last day
- 90-day probation period: Start date → end of probation (don't forget weekends count)
- Loan term: A 1-year loan isn't always 365 days — calculate from disbursement to maturity
- Visa duration: Tourist visas specify exact days — count carefully to avoid overstay
- Project sprint: 2-week sprints = 14 calendar days; confirm start/end dates before planning
- Interest calculation: Many loans use actual/365 or actual/360 day count conventions
Privacy and Data Handling
All date calculations run locally in your browser. Dates are not sent to any server and are not stored.
Frequently Asked Questions
Does the count include both the start date and end date?
The default calculation counts the gap between dates — the start date is day 0 and the end date is the last day. So from January 1 to January 5 = 4 days difference. If you need to count both endpoints as full days (e.g., "inclusive" counting for an event that runs Jan 1 through Jan 5), add 1 to the result: that's 5 days total. The convention varies by context — loan agreements often specify "days" inclusive or exclusive, so check the wording of any legal document you're working with.
How many days are in a year for financial calculations?
It depends on the day-count convention used by the financial product. The main conventions: Actual/365 — actual days divided by 365 (used for US Treasuries), Actual/360 — actual days divided by 360 (common for corporate bonds, some mortgages), 30/360 — assumes 30 days per month regardless of the calendar (used for fixed-rate mortgages in some markets). For personal financial planning, actual/365 is the most common and intuitive. Check your loan agreement for the specific convention.
What's the fastest way to count days until a future event?
Enter today as the start date and the event date as the end date. The calculator shows the exact number of days remaining. For recurring use (e.g., tracking days until a deadline that changes), bookmark the calculator with today's date pre-filled or use a calendar app with built-in countdown features. For business use, knowing both calendar days and working days matters — a 30-day deadline that starts on a Monday includes 22 working days.