Days Between Dates Calculator
Find the exact number of days, weeks, and months between two dates. Useful for project deadlines, travel, and event planning.
Total Days
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Total Weeks —
Approx. Months —
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Result Date
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Total Days —
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Total Days
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Total Weeks —
Approx Months —
Approx Years —
Total Hours —
Total Minutes —
Business Days (approx) —
How to Use This Calculator
- Enter Date 1 (year, month, day).
- Enter Date 2 (year, month, day).
- The results instantly show the difference in days, weeks, and approximate months.
Formula
Days = |Date 2 − Date 1| (in milliseconds ÷ 86,400,000)
Weeks = floor(Days ÷ 7) | Months ≈ floor(Days ÷ 30.44)
Example
Example: Jan 1, 2024 to Dec 31, 2024 = 365 days (52 weeks, 11 months).
Frequently Asked Questions
- The calculator finds the absolute number of calendar days separating the two dates. It converts each date to its Unix timestamp (milliseconds since January 1, 1970), subtracts the two values, and divides by 86,400,000 (milliseconds per day). For example, from January 1, 2024 to December 31, 2024 is 365 days because 2024 is a leap year with 366 calendar days but the start and end are not both counted. The result is always a whole number rounded to the nearest integer, so you do not need to worry about daylight-saving-time clock-change days skewing the count.
- The standard calculator counts all calendar days, including weekends and holidays. For business-day counting — where Saturdays, Sundays, and public holidays are excluded — use the dedicated Workday Calculator on this site. A typical five-day workweek has 5 out of every 7 calendar days as business days. For quick estimation, multiply calendar days by 5/7 (about 0.714) and subtract any holidays in the period. For example, a 30-calendar-day period contains roughly 21 business days before holiday adjustments, which aligns with most monthly billing and delivery estimates.
- No — the calculator uses the absolute difference, so entering the later date first or the earlier date first gives the same positive result. For example, Jan 1 to Dec 31 returns 364 days, and Dec 31 to Jan 1 also returns 364 days. The absolute value is taken by wrapping the subtraction in Math.abs(), so negative timestamps are never shown to the user. If you want to know whether a date is in the past or future, use the Date Calculator or Age Calculator, which show direction. For countdown purposes, simply read the result as "days remaining" when date 2 is after today.
- The week count is exact: the calculator floors total days divided by 7 to get complete weeks, with the remainder being days. For example, 30 days = 4 weeks 2 days. The month count is approximate because calendar months are not equal in length. The calculator divides by 30.4375 (the average length of a month over a 400-year Gregorian cycle: 365.2425 ÷ 12). For most planning purposes this is accurate enough. If you need exact calendar months, use the Age Calculator or Date Calculator, which step through actual month boundaries and correctly handle February and month-end edge cases.
- Yes — enter today's date as Date 1 and your event date as Date 2. The result shows exactly how many days remain. For example, if today is May 12 and your event is July 4, you would enter May 12 and July 4 for the current year and get 53 days. Common uses include counting days until a vacation, a project deadline, a product launch, or a legal filing date. For recurring countdowns that update automatically each day, try the Countdown Calculator, which always uses the current date as the starting point without manual entry.