How many days between two dates. What date is 90 days from now. Which weekday a date falls on. Three questions that are surprisingly easy to get wrong in your head.
Open the date calculator →This causes more errors than leap years. Ask how many days between 1 March and 3 March and there are two defensible answers:
| Method | Result | Used for |
|---|---|---|
| Exclusive (difference) | 2 days | Interest, age, elapsed time, most maths |
| Inclusive (both ends) | 3 days | Hotel nights vs days, hire periods, holiday entitlement, some contract terms |
Legal deadlines add a third convention: periods often run from the day after the triggering event, and if the final day falls on a weekend or bank holiday it may roll to the next working day. When money or a deadline depends on it, read the actual wording rather than trusting any calculator, including this one.
A year is a leap year if it divides by 4, except century years, which must divide by 400. So 2000 was a leap year, 1900 was not, and 2100 will not be. Any date range spanning 29 February 2024 or 29 February 2028 gains a day.
Months are not a fixed length, so "one month after 31 January" has no single correct answer. The usual convention — and the one Palarid follows — is to clamp to the last valid day, giving 28 February (or 29 in a leap year). Different systems handle this differently, which is why a subscription started on the 31st can bill on unexpected dates.
Excluding weekends is straightforward. Excluding bank holidays is not, because the UK does not have one set: Scotland has 2 January and St Andrew's Day, Northern Ireland has St Patrick's Day and the Twelfth, and England and Wales have neither. A "10 working days" clause can resolve to different dates for different parties.
Everything is calculated in your browser. No account, no server, and it keeps working with no connection.
Nearly always inclusive versus exclusive counting. Occasionally a leap year. Very occasionally a time zone, if the tool is comparing timestamps rather than calendar dates — Palarid compares calendar dates.
Not for whole days. It matters only when counting hours across a clock change: in the UK the last Sunday in March has 23 hours and the last Sunday in October has 25.
Well beyond any practical need in both directions. Be aware that dates before September 1752 in Britain are Julian, not Gregorian — the calendar switch removed 11 days, so historical dates need care regardless of the calculator.
Time zone converter · Unit converter · QR code generator · Pomodoro timer
Palarid is free and private. See all tools → · Trust Centre · About