Day Counter
Count days, weeks and months between two dates. Useful for project timelines, anniversaries and event planning.
How to use the Day Counter
- Enter your inputs into the Day Counter above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The day count formulas
Days = Σ days in each calendar month between · · · Weeks = Days / 7 · · · Months = full calendar months elapsed
Day counting is straightforward when leap years and calendar month lengths are handled correctly. "Months" is the count of full calendar-month elapsed, not days/30.
Worked example
From 2025-12-15 to 2026-05-26: 162 days, 23 weeks (162/7 ≈ 23.1), or 5 months and 11 days.
Frequently asked questions
Is the day counter inclusive of both endpoints?
Typically counts the gap (days BETWEEN), so neither endpoint is included. To include both, add 1 to the result. Always state your convention.
How are months counted?
Calendar-month based: a full month elapses each time the day-of-month value of the start date is reached again. From Jan 15 to Feb 15 = 1 month, not 31/30.4.
What about business days?
Business day counting excludes weekends and holidays. The calculator offers this as an option for project planning purposes.