Calendar Days Calculator

It counts the length of a date range in three ways at once: calendar days, full calendar months and partial calendar months. Both selected dates are included in the count, so a range that starts and ends on the same day is one calendar day. Pick a start date and an end date, click Calculate, and you get all three numbers.

A full calendar month is a month the range covers completely, from its first day through its last day. A partial calendar month is any month the range touches, even by a single day. For 15 January to 10 March 2026 you get 55 calendar days, 1 full calendar month (February) and 3 partial calendar months (January, February, March).

No. It counts calendar days, so weekends and public holidays are part of the result. That is what you need for probation periods, notice periods and length of service, which run in calendar time. If you need working days instead, that depends on each employee's work schedule and holiday calendar — Calamari does that inside the Time Off module.

Checking when a probation period or notice period ends, calculating length of service for a seniority-based entitlement, and verifying the numbers behind a prorated leave calculation. The three month counts also map directly to the proration methods in our Prorata Calculator, so you can see which method changes the result and by how much.

Yes. Dates are calculated in UTC from the actual calendar, so 29 February and multi-year ranges are counted correctly, with no rounding or approximation.