Date Difference Calculator
Work out the gap between two dates in days, weeks, months and working days, with the ambiguous units flagged.
About this tool
Calculates the distance between two dates and gives the answer in every unit that has one: days, weeks, working days, and the calendar difference in years, months and days.
**Days are exact. Months are not.** "One month" is 28, 29, 30 or 31 days depending on which month, and the difference between 31 January and 28 February is genuinely ambiguous — one month, or a few days short of one? Both readings are shown rather than one being chosen quietly, because "3 months" and "89 days" are not in disagreement; they answer different questions.
Working days exclude Saturdays and Sundays and **no public holidays at all**, anywhere. Those vary by country, region and year, and a tool that guessed at them would be wrong for most people using it.
Times of day are accepted and used. Without one, both dates are taken at midnight UTC.
Common questions
Why are there two answers for months?
Because the question has two readings. The calendar difference counts month boundaries crossed; the day count divided by an average month length gives a proportion. From 31 January to 28 February, one says "28 days" and the other says "just under a month", and neither is wrong.
Are public holidays excluded from working days?
No. Holidays differ by country, by region within a country, and by year, and several move. Guessing would be wrong for most people, so working days here means weekdays and nothing more.
Is the end date included?
Both counts are shown. The difference between them is the classic off-by-one in date arithmetic: a booking from Monday to Friday is four nights and five days, and which you want depends on what you are counting.
What date formats work?
ISO dates (2026-03-15) are unambiguous and always correct. Written forms like "15 March 2026" work too. Avoid 03/04/2026 — that is two different dates depending on where you are, and this reads it as year-month-day or month-day-year rather than day-month-year.