onlinecalculator.me

Free online date difference calculator

This calculator tells you exactly how many days, weeks, months, or business days sit between two dates.

Difference
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Total days
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Total weeks
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Business days
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Total hours
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Total minutes
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About this calculator

How to use

  1. Enter a start date and an end date.
  2. Use “Through today” or “Through year end” for common scenarios.
  3. Read the results — years, months, days, total days, business days, hours, and minutes.
  4. Press “Share with my numbers” to copy a URL with your dates.

How dates are calculated

Total days: The number of 24-hour periods between midnight on the start date and midnight on the end date. Uses UTC internally to avoid daylight-saving-time artifacts.

Years, months, days: Calendar subtraction — subtract full years, then remaining months, then remaining days, borrowing from the larger unit when necessary.

Business days: A loop counting Monday–Friday days between the two dates (exclusive of the end date, per common convention).

Hours and minutes: total days × 24 and × 1,440 respectively.

Worked example

From January 1, 2025 to June 30, 2025:

  • Calendar: 5 months, 30 days (or 0 years, 5 months, 29 days by strict subtraction)
  • Total days: 180
  • Business days: 129 (Jan–Jun 2025, Mon–Fri)
  • Total hours: 4,320

Notes

  • The calculator uses UTC date math to avoid incorrect results during daylight-saving-time clock changes.
  • Business days exclude weekends only. Add or subtract your region’s public holidays manually.

Frequently asked

How are years, months, and days calculated?
The calculator uses calendar arithmetic — subtracting dates step by step to find full years, then remaining months, then remaining days. This accounts for months of different lengths and leap years, matching how people naturally think about time spans.
How are business days counted?
Business days are weekdays (Monday through Friday). The calculator loops through each day in the range and counts only non-weekend days. Public holidays are not excluded, since they vary by country and region.
Why might the months shown differ from dividing total days by 30?
Calendar months have 28–31 days, so dividing by 30 gives an approximate answer. The calculator uses exact calendar subtraction, which is more accurate for planning purposes.
Can I calculate dates in the past or future?
Yes. Enter any valid dates in either order. If the end date is before the start date, the calculator notes it and shows the absolute difference.
What are the quick preset buttons for?
"Through today" sets the end date to today. "Through year end" sets it to December 31 of the current year — useful for planning how many days remain in the year.